The Sapling

Released: Dec 12, 2019
Platforms: WindowsLinux
Last updated: 05 Sep 2026, 06:36 GMT

Updates & announcements

20 posts

30 Jun 2026Developer post
The stream is almost halfway! Watch together with the dev in 2 hours
As you might know, at the moment I'm running a long livestream, simulating evolution 24/7. It's all epxplained in this video: We've been able to follow the planet Wright-2b for almost a week now, and the moving continent (named 'Rupert' by the community) is about halfway its jour
As you might know, at the moment I'm running a long livestream, simulating evolution 24/7. It's all epxplained in this video: [previewyoutube=J7aXTBqSVYw;leftthumb][/previewyoutube] We've been able to follow the planet Wright-2b for almost a week now, and the moving continent (named 'Rupert' by the community) is about halfway its journey. Many interesting things are happening, like:

The two main continents are each hosting their own plant family: the western one is mostly red, the eastern one is mostly blue.
The ocean was covered in floating algae for days, until the animals evolved eggs that could handle stronger ocean currents, which caused a huge boom in filter feeders, causing all algae to go extinct.
The ecoystem on the larger continent (named 'Deus Agriculturae' by the community) is mostly based around fruit and fruit eaters.

To celebrate making it until here I (the dev Wessel Stoop) will be present in the chat tonight at 1900h UTC (2100h CEST, 1200h PDT, 1500h EDT)! Come watch the stream with me at twitch.tv/wesselstoop
Original post
25 Jun 2026Developer post
Wright-2b is live!
Streaming evolution simulation indie game The Sapling, 24/7 for 2 weeks: We started on planet Wright-2b with a simple alga and underwater animal, turned on random mutations, and now we watch what evolves. Introduction to the project: Introduction to the world:
16 May 2026Developer post
Patch v13.71
Balancing and fixes for animals Various legs besides the body now have special requirements for the animal to have more than 1 set of limbs, to make them look more natural (already in the previous patch logs, but now it's working) Sessile animals with moving juveniles now actuall
Balancing and fixes for animals

Various legs besides the body now have special requirements for the animal to have more than 1 set of limbs, to make them look more natural (already in the previous patch logs, but now it's working)
Sessile animals with moving juveniles now actually move to the ocean floor and stop moving as adults (thanks, Cody Beaver, Cringus Ringus, Spectator, Acarlis, mic biology!)
Idem for ocean floor walkers (thanks, Ancient Relic!)
Optimized species population size tracker in situations with many species

Balancing and fixes for plants

Grass is now removed from a cell when eaten (thanks, esportfrank!)
Wildfire now removes grass, and grass won't be able to grow there for a while
Plant subspecies will now always have the same color as their parent species, to make it easier to identify which plant is which species
Tweaked the chance of algae evolving into plants

Working on the weight system

Made max weights for flying and in particular gliding higher, so development of flight is more likely
Weight now increases with body size, making giant flying things less likely (thanks, Warlor-vir!)
Individual torso segments now have less influence on the final weight to compensate for the above
Now the 'halve weight' icons are used everywhere, so you can see the weight in more detail
Removed ugly floating points that could sometimes pop oup in the UI

Introduced savefile format 16

Memory/savefile optimization: the game now prunes extinct subspecies that the player couldn't see anyway
Added support for automatic continental drift
When loading, fixed the explainer text about which formats are supported

Various little editor fixes

Adding seasons and then hitting 'randomize all' no longer messes up the planet tilt (thanks, SethMMX!)
Plus and minus keys now also control zoom in the alga and fungus editors (thanks, Daruka!)
When dragging the 'slow moving tube feet' and 'sessile foot' body parts, they now have the correct color instead of white

Misc

Clicking a species in the cladogram view now shows a subtree starting from that species, making it easy to study part of very large trees

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
07 Apr 2026Developer post
Patch v13.57
Balancing and fixes for plants Major rebalancing of leaf statistics, so you will more variety in the leaves evolving Bioluminescent flowers and fruits now cost slightly more energy (thanks, Warlord-vir!) Prevented plants slowly taking over areas where they shouldn't be able to su
Balancing and fixes for plants

Major rebalancing of leaf statistics, so you will more variety in the leaves evolving
Bioluminescent flowers and fruits now cost slightly more energy (thanks, Warlord-vir!)
Prevented plants slowly taking over areas where they shouldn't be able to survive because of the moisture
Prevented another way to make illegal fruits, causing the game to glitch (thanks, Svelyrai!)

Balancing and fixes for animals

Added a simple balance system to prevent animals that look like they will fall over from evolving
Various legs besides the body now have special requirements for the animal to have more than 1 set of limbs, to make them look more natural
Animals with various arthropod legs can no longer accidentally swim underwater (thanks, Abel Pérez Pastor!)
Animals with only gasbags and no other limbs are no longer considered valid in the editor (thanks, Kaanaykas!)
Noise producing wings now add a bit of base attractiveness (thanks, Warlord-vir!)
The animal editor UI now shows attractiveness as if the animal is displaying its attractive organ, not base attractiveness (thanks, Warlord-vir!)
Animals that can not move at all, but are also not sessile, will no longer reproduce on land

Fixes for custom terrain

Fixed removing land and then drawing again causing various glitches
You no longer accidentally draw land mid simulation when the cursor is over UI (thanks, Kminek99!)
Fixed incorrect climate zone after saving and loading (thanks, Kminek99!)

Misc

Lots of work on a revised stream mode for an unannounced streaming project
Fixed wildfire caused by lava not appearing in the correct place on the map
The red 'change macro alga height' handle no longer appears when editing plankton (thanks, Kaanaykas!)
Pressing space in the main menu no longer restarts the background music (thanks, Filiberto Juanceto, Hexadexx, Izaiah Bradford!)
Fix still seeing extinct organisms when turning on 'exclude instinct' in the new cladogram view

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
17 Mar 2026Developer post
Patch v13.52
Working on land animal evolution Made the evolution of land animals more likely Animals with aquatic eggs that can only walk very slowly are now considered land animals if they also swim very slowly If there are only very few land species, subspecies branch off into their own spe
Working on land animal evolution

Made the evolution of land animals more likely
Animals with aquatic eggs that can only walk very slowly are now considered land animals if they also swim very slowly
If there are only very few land species, subspecies branch off into their own species earlier
Visualization: only reuse a model for an existing species if the subspecies has the same limbs. If not, a more accurate model will be used, but it will be recolored to match the original species color so you can quickly spot what animals are what species.

Other changes to the simulation

Animals no longer reproduce if they have a lot of neighbors, preventing extremely crowded simulations
Fixed a grass mutation bug that could cause green areas without a visible grass (thanks, Azul1462!)

Improvements for the cladogram

The simulation in the background now pauses if you open the cladogram, and resumes again if you close it
If you click when hovering a species, you will now be taken to the species detail view
Parent species for plants are now saved correctly, so algae and plants show up in the same cladogram

Plant editor fixes

Fixed plant size buttons always leading to the grass size (thanks, Benjamin Santiago, Mazus, Lopai, Amargarrex, SethMMX, mayr777, Felipe, leofunsit, Ethan Cameron, Insects india, BAK, CRJ, Zoekunce!)
Fixed a workflow that could cause an illegal fruit (thanks, Svelyrai!)

Animal editor fixes

Fixed animal problem tooltip showing up on top of instinct list view (thanks, Jordan P, insects india, Kaanaykas!)
Fixed the attractiveness statistic for mouths and limbs not showing up (thanks, Warlord-Vir!)

Misc

Prevented various planet editor buttons becoming unresponsive when using them in manual stats mode (Thanks, TheOwlManBranch!)

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
07 Mar 2026Developer post
Patch v13.49
More work on the project to make the game easier to understand Added a habitat map for the plant and animal editors, so you can quickly see where in your world this planet will survive Moved the 'this organism has a problem' message out of the editor side bar for editors, so it h
More work on the project to make the game easier to understand

Added a habitat map for the plant and animal editors, so you can quickly see where in your world this planet will survive
Moved the 'this organism has a problem' message out of the editor side bar for editors, so it has more space for a more detailed explanation
For the plant editor, merged the energy usage and energy profit bars into a single colored energy bar
For the plant editor, made the 'amount of offspring' visualization textual
For the planet editor, changed the season and ring toggles in the planet editor to have icons
Added stretched arrow buttons to tutorial

Redesigned the ready/discard buttons in all editors

The alga and fungus editors now also have a discard button
Moved the 'discard' buttons next to the ready button for every editor
The 'ready' buttons are now recolored to fit the style of each individual editor

Fixes for the new cladogram

Root species are now ignored if they are extinct and have no decendants (thanks, Ultraneongodpet and UnitedKibbles31!)
Fixed the color of 'exclude extinct' button when hovered
Prevented the cladogram glitching out when there are not root species
Fixed missing lines for species that went extinct but were reintroduced

Misc

Prevented floating leaves or seeds in the editor when using the CTRL button (thanks, Chared!)
In the 'skipping time' view, made sure the 'recent mutations' label was readable also on smaller screens

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
24 Feb 2026Developer post
Patch v13.46
A completely new cladogram view I've replaced the old cladogram view, because playtesting quite consistently showed that nobody was using it. The game is now using a completely new chronogram approach as can be seen in both Species ALRE and The Bibites. It should give a much bett
A completely new cladogram view
I've replaced the old cladogram view, because playtesting quite consistently showed that nobody was using it. The game is now using a completely new chronogram approach as can be seen in both Species ALRE and The Bibites. It should give a much better 'zoomed out' overview of which species branched off from which one at what point in time. Even though previous changes to speciation drastically reduced the number of species, the trees in this new cladogram/chronogram can grow quite large, so this view has been heavily optimized. Perhaps surprisingly, by far the hardest part were the resizable scrollbars that allow you to navigate large trees. I believe most issues have been fixed, but they sometimes still revert (making the view go left instead of right) for reasons I do not understand yet.
UI mutation fixes

Fixed the animal mutation view no longer always showing the nr of plant species as 25 (thanks, Jotbe!)
When selecting mutation rates, the UI now shows the correct max value of 35% (thanks, generaldisbelief, JupiterHater!)
When closing and reopening the mutation chance pickers, they now continue showing the correct value

Introducing the next version save file format

Fixed body stance not being saved correctly for juveniles and sex B-F (thanks, AncientRelic!)
Fixed speciation threshold not being saved correctly, which caused saving+loading to delay speciation

Misc

Made the heart icon to indicate mating less frequent at high timespeed (thanks, Jupiter Hater!)
In the planet editor, switching to the rotating planet and back to the map now only shows the drawing circle when needed (thanks, TheSpaceCore69!)

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
14 Feb 2026Developer post
Patch v13.45
Major simulation change If an animal is in a location that contains food, it will no longer leave that location until all food is gone (except plankton, which requires swimming through). This makes it a lot easier to keep various animals alive, addressing a recurring complaint...
Major simulation change
If an animal is in a location that contains food, it will no longer leave that location until all food is gone (except plankton, which requires swimming through). This makes it a lot easier to keep various animals alive, addressing a recurring complaint... but also leads to crowded environment (and, following that, possibly low FPS) more quickly. Thanks Luka159, Generaldisblief, Wind_kaffee!
Various changes to make the simulation easier to understand

When placing down organisms, a minimalist version of the requirements panel is shown floating near your cursor
Took the 'will survive here' text out of the requirements panel
Set the maximum mutation rate to 35%, as higher mutations only cause a lot of small new subspecies that never gain enough traction to become full species
The time jump view now shows mutation events, so you know evolution is happening even when there are no new species
Food types icons now have a tooltip, explaining what they are and how they work
Added various tooltips to the animal editor
Redesign the underwater speed stats in the animal editor to be easier to understand at a glance
Sessile animals no longer show potential (but unused) movement statistics, which was confusing to players (thanks UltraNeonGodPet, Slurp!)

Animation fixes

Only show the egg laying animation when the animal is actually laying the egg, not already when it wants to
To prevent aquatic animals floating perfectly frozen sometimes, immediately start showing the aquatic idle animation when it's not playing any other

Fixes for terrain textures

Season changes no longer cause terrain to becomes a single color (thanks Cody_beaver!)
The planet editor no longer forgets to highlight continents after doing it once
In the planet editor, when editing seasons and THEN drawing more land, this new land is no longer incorrectly made part of previous continent

Misc

Lowered fungus speciation threshold (thanks, Jotbe83!)
Newly added animal models now get a random rotation, so they're not all facing the same way

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
03 Feb 2026Developer post
Patch v13.44
Overhauled optimization mechanism that decides which 3D models to show Building procedural 3D models on the fly is expensive; on most modern hardware, showing an accurate model for each plant and animal in realtime is not feasbile. Therefore, as an optimization mechanic, until no
Overhauled optimization mechanism that decides which 3D models to show
Building procedural 3D models on the fly is expensive; on most modern hardware, showing an accurate model for each plant and animal in realtime is not feasbile. Therefore, as an optimization mechanic, until now only populous species got their own models, which was an acceptable approximation for some time. However, ever since I made a change to how speciation works a few years back, causing many more species, a lot of players noticed this optimization mechanism partly ruined the gameplay experience for them. The revised speciation patch two weeks ago, which significantly decreases the number of species, was already a first phase to fix this problem. This week, I take it a step further and introduce a revision to the mechanism itself. In this new approach, the game will still prebuild the most populous species; the main difference is what happens if the species model is NOT available. Before, it would default to the most used species. Now, instead, it will use a so-called 'library profile', which is a summary of the most important bodyparts. For animals, this entails which eyes, mouth and limb the animal has. If an animal with a similar profile is available, it will be used. Otherwise, the game will quickly create it from scratch and store it for later.
Changes to animal mutation

Made the threshold for animal speciation more dynamic, so it happens earlier when there are fewer species (thank you, Flyer24, SethMMX, CommonRaccoon, AntRuler13, Ewumd68, Liam, QuaLITyCli!)
Fixed a problem where in some cases animal mutations happened so often that subspecies never got populous enough to form a new species

Made it easier to keep your species alive

Lowered the energy cost for animal babies for larger species
Lowered the energy buffer size when giving birth (extra required energy, so the mother does not immediately starve afterwards), in particular for older animals

Started a project aimed at making the simulation easier to understand

Revised the tooltips for the sandbox panel buttons and made them show up earlier (from 2 seconds to 3/4 second)
Added various new and more detailed tooltips to the planet editor
Added various new and more detailed tooltips to the plant editor

Misc

Limited the egg laying animation to walking animals
Fixed an animal editor bug that occurred when adding a sessile foot to upright juveniles (thanks, DJ_999!)

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
24 Jan 2026Developer post
Patch v13.41
Completely overhauled how species are detected So far, species classification was based on the features of an organism. Simply put, if a plant evolved a new type of leaf, or an animal evolved a new type of fin, the game decided this was a new species, without giving it further th
Completely overhauled how species are detected
So far, species classification was based on the features of an organism. Simply put, if a plant evolved a new type of leaf, or an animal evolved a new type of fin, the game decided this was a new species, without giving it further thought. For longer simulations, this resulted in hundreds of thousands of species (99% of which only had 1 organism before going extinct), eating up RAM and disk space. Now, instead, the game only considers a subpopulation of a species a new separate species if it's large enough. This solves many of the tech problems and seems to be more intuitive to players, but also brings new challenges. Most notably, large species might have one or more subspecies that are different from the main species in one way or another, but not large enough to justify branching it off; think of a single stemmed plant having a grass subspecies, or a herbivore species with a subspecies that also eats meat.
Optimization

Fixed huge memory leak in the planet editor, causing the game to crash during longer sessions (thanks TheSpaceCore69, Feather!)
Fixed huge memory leak when drawing statistics, causing the game to crash during longer sessions (thanks Deven Lobua!)
Moving the secondary color sliders in the animal editor now updates the colors in real-time
Removed a very frequent log message when (auto)saving which made it very slow

Fixes for sessile and/or upright animals

Making upright bodies longer now makes it longer on top (instead of at the bottom)
Newly extended torso position is now closer to the cursor
Extending the torso position after adding sessile foot no longer results in illegal animals (thanks theGreyHanded, Flyer24!)
Animals with a sessile foot are now always sessile, even if it also has fins (thanks igloo!)

Improving behavior of keyboard controls

'Escape' can now also be used to leave animal placement mode
The main button to skip the intro is now space (but x also still works)
Fixed UI glitch after doing escape + click in the species list view

Discovered and fixed two causes of corrupt save files

The mechanism that moves sessile feet to the side of the animal if mutated into something else sometimes also triggered when it shouldn't, resulting in illegal animals (thanks MarcoDBAA, Ed Balls!)
When loading scenarios, the climate zone information was not provided, preventing loading scenarios at all (thanks Bird!)

Misc

Mutated body parts no longer retain the descriptive label (when hovering them in the editor) of their ancestors (thanks TaterTot!)
'Montane' climate zone boundary now depends on ocean height (thanks Slurp, Chared!)
Fixed maximum population size statistics for species
Fixed wrong volcano texture after eruption

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
10 Jan 2026Developer post
Patch v13.40
This is the first time the new movement update is available to everyone, regardless of whether you chose the beta. A quick overview of all new features: This is what has changed since the movement update patch last week. Fixes for juveniles and the red torso length handle in the
This is the first time the new movement update is available to everyone, regardless of whether you chose the beta. A quick overview of all new features: [previewyoutube=VU7r7Wm7Wa0;full][/previewyoutube] This is what has changed since the movement update patch last week.
Fixes for juveniles and the red torso length handle in the animal editor

When changing posture of adults, and juveniles have the same posture, also change it for the juvenile... fixes unexpected behavior and ALSO prevents crashes related to accessories on top (thanks, Shemariguess, al!)
For juveniles, have the handle at the correct position also when the posture is different from the adult form
Fixed handle initially not responding when looking at the juvenile form of an animal
Made sure the handle is at the correct position when entering the editor

Various fixes for volcanoes

Fixed not being able to highlight a volcano directly after creating it
Moving a volcano now also moves the hole (thanks TaterTot, Mike the Drawman!)
Fixed problem with hability calculations that caused volcanoes to be linked to existing landmass indices (thanks TaterTot!)
Volcanoes that were removed by the player can no longer erupt (thanks TaterTot!)
Volcanoes no longer remain highlighted after you selected which one should erupt

Fixed various unlocking mechanics

In the plant editor during the scenarios, the correct plant traits are unlocked also when mutating a plant two times in a row (thanks TaterTot!)
Sandbox mode now requires finishing the first scenario again
You can no longer click and play scenarios that are not unlocked yet (thanks VoidHydra!)
The 'cool completionist' achievement is now only awarded when all scenarios are actually beaten (thanks VoidHydra!)
Fixed the 'Courageous Carnivore' achievement never firing (thanks al!)

Fixes for the sandbox

Disaster panel: moisture button no longer influences ocean moisture level
When randomly generating a planet, gravity is now also randomized instead of always being super strong (thanks TaterTot!)

Misc

Made sleeping and giving birth animations slightly less weird for upright animals (thanks Parrokeet!)

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
03 Jan 2026Developer post
Patch v13.39 (beta only)
Improved upright bipeds Added arm swing animation for animals with arms Upright bipeds no longer have their feet clip through the ground when placed Upright bipeds no longer slowly sink into the ground when walking Prevented walking animation problems for creatures with limbs tha
Improved upright bipeds

Added arm swing animation for animals with arms
Upright bipeds no longer have their feet clip through the ground when placed
Upright bipeds no longer slowly sink into the ground when walking
Prevented walking animation problems for creatures with limbs that do not walk, like fins or arms

Other animation improvements

Revised walking animation parameters for the 'long but lightweight leg' and 'sturdy' limbs
Remodeling the hopping leg to better work with the procedural walking system
Improved special animation for 'water surface walker' (thanks Komodo, TealClaw, Jupiter hater!)
Avoid some weird looking idle animations for animals with arthropod legs
Created special dying, sleeping and egg laying animations for animals with arthropod legs

Fixes for seasons

Climate zones are now updated when a season changes mid simulation
When looking at the statistics overlay while the season changes, the terrain no longer becomes solid white or black (thanks Izaiah Bradford!)

Fixing terrain height bugs

In the planet editor, when you start drawing land on top of an existing mountain, the new land will now be even higher than that mountain so you can see what you are drawing (thanks UltraNeonGodPet!)
Fungi are now repositioned if you change the height of a continent (thanks Shemariguess!)

Misc

Made greenhouse scenario way easier by removing the whole carnivore requirement

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
27 Dec 2025Developer post
Patch v13.33 (beta only)
Resurrected the scenarios Tested and rebalanced all scenarios to work with the new features of the movement update Redesigned the soil statistic button to have a planet icon Added new terrain overlay steepness stats and climate zones to all scenarios For all scenarios, added new
Resurrected the scenarios

Tested and rebalanced all scenarios to work with the new features of the movement update
Redesigned the soil statistic button to have a planet icon
Added new terrain overlay steepness stats and climate zones to all scenarios
For all scenarios, added new limbs to 'anchored body parts' (which don't require mutations to reach) wherever it made sense
Prevented plants spreading all of their seeds in the beginning of their life (which could happen with large seed surpluses that the disaster scenario requires)

Resurrected the daily challenge

Linked the new random terrain generator to the challenge generator
Made the 'ocean floor walker' leg always unlocked, to give players easy access to the new arthropod limbs if they want to
Disabled terrain editing tools
Fixed the upper half of the 'let's go' button not registering clicks

Fixes for small map sizes

Drawing stats no longer causes the game to freeze (thanks, Jupiter hater!)
Switching to smaller map sizes while in manual stats mode no longer causes the game to freeze (thanks, Jupiter hater!)
Meteorites craters now appear on the correct location (thanks, Jupiter hater, azul1462, Col. caboose!)
Hovering continents is now (much) more precize
Volcano smoke now appears above the volcanoes
Highlighting continents now continues to work after editing the terrain

Polishing the walking animation

Revised walking animation parameters for the 'hoof', 'webbed', 'sturdy walker', 'very sturdy' limb, 'hangs upside down', 'lightweight webbed foot' and 'sharp talons' limbs
Remodeled 'fast two-toed runner' to better work with the walking animation

Fixes for upright animals

You can no longer by accident attach the sessile foot to a slot that is not the bottom one
Fixed how animation bones are connected for upright animals

Misc

Fixed the limb stats in the animal editor showing the max weight for walking where it should show max weight for climbing (thanks UltraNeonGodPet!)
Made fade animation more robust to edge cases
Made it possible to select continents very far away from the camera mid simulation

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
20 Dec 2025Developer post
Patch v13.31 (beta only)
Reintroduced the 'randomize all' button The new version of the button generates small and large landmasses at random, using the new continent system. They can be moved and changed by the player. Most of the other random changes (like temperature, moisture, rings, etc) could be re
Reintroduced the 'randomize all' button
The new version of the button generates small and large landmasses at random, using the new continent system. They can be moved and changed by the player. Most of the other random changes (like temperature, moisture, rings, etc) could be reused from the previous iteration of this button, but they're now also linked to the climate zone system so you can quickly see what has been generated for you.
Polishing walking animations

Fixed 'lightweight foot', 'fast hopping' and 'hopping' limbs not showing the hopping animation
Made it possible for some (fast) legs to lift the feet higher, so it looks more like running
Remodeled 'clawed, walking on toes' limb to better work with with the walking animation system
Made it less likely that legs move in the incorrect order for any nr of legs (2, 4, 6, etc)
Polished walking animation settings for 'knee', 'besides the body', 'long toes', 'mountain climbing hoof' and 'adhesive pads' limbs
Revised arthropod walking limb animation bones to work better with walking animation

Fixes for upright/sessile animals

Fixed mouths on top or near the bottom duplicating, causing illegal animals (thanks theGreyHanded!)
Fixed sessile animal's diets not being tracked (thanks Ultraneongodpet!)
Made it so that the sessile foot mutate into jets (at random) it also moves the jets to the side of the animal (thanks Ultraneongodpet!)

Misc

Fixed exterminating alga spores

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
13 Dec 2025Developer post
Patch v13.30 (beta only)
More work on animation Added sleeping animations: animals squatting, moving head down and to the side Added egg laying animation (best visible in animals with a tail, because they move it up) Optimized specializing animations to player designed animals, and made it possible for a
More work on animation

Added sleeping animations: animals squatting, moving head down and to the side
Added egg laying animation (best visible in animals with a tail, because they move it up)
Optimized specializing animations to player designed animals, and made it possible for an animation to only affect the first limbs (instead of all of them)
Changed animation where tailless aquatic animal swim with their fins: they now only move the first set of fins
More natural flying animation: made downwards wing movement faster and upwards wing movement slower
Made undulating swimming animation symmetrical

Working on limb body parts

Added animation weights to 'ocean floor walker', 'filiform', 'hopping', 'spindly' and 'swings between branches' limbs (which reveal they need a separate set of animations)
Went over all limb stats in detail for a first balancing iteration

Fixes for seasons in the planet editor

Previewing seasons in the planet editor now shows the correct stats and climate zones (thanks azul1462, ultraneongodpet)
Going to the season editor no longer toggles the planet editor to manually drawn statistics
Turning off seasons now removes the season indicator
If you are looking at another season than season A while turning off seasons, update the terrain overlay

Other planet editor fixes

The correct map editor tool button is already selected when you enter the editor
Fixed the continent highlighting textures carrying over to a new game session (thanks azul1462, Taylor Lilius, DayzeDaisy!)
Made it so the planet editor always uses gravity for planet size in spherical mode (rotating planet), but map size when showing the flat map view (thanks saralb123!)
Adding planet rings when manually drawing stats no longer causes the planet editor to freeze
Increased default deep ground water (thanks Ultraneongodpet!)

Small UI fixes

Made it so pressing ESC when something else is open first removes that thing, preventing situations where it overlaps with other UI
Prevented UI overlapping when a dropdown is open and you click an organism

Sessile animal fixes

Turns out my fix for the ballistic mouth broke all other mouths on top *facepalm*. Now they all work. (thanks Ultraneongodpet!)
Fixed problem where lowering the terrain height did not update how high sessile animals grow
'Slow moving tube feet' no longer swim around like they're not sessile at all (thanks Cody beaver!)

Misc

Updating the terrain mid simulation while the camera is underwater will no longer lead to unexpected moiré patterns on the ocean floor

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
06 Dec 2025Developer post
Patch v13.27 (beta only)
Introducing save file format 13 Includes steepness of the terrain Remembers manual mode in the soil statistics view Updated the loading view explanation (which formats are supported) Working on flight with insect wings Animals with insect wings no longer stop moving when flying a
Introducing save file format 13

Includes steepness of the terrain
Remembers manual mode in the soil statistics view
Updated the loading view explanation (which formats are supported)

Working on flight with insect wings

Animals with insect wings no longer stop moving when flying at normal time speeds
Actually play the fluttery flight animation in the game
Added aerial idle animations for rapid and fluttery flight styles
Cleaned up buzzing noise, made it loopable, and start and stop it together with the flight animation
Regular noise and flight noise are no longer mixed up
Made the buzzing noise you hear (as example) in the editor much shorter
No longer visualize movement noise with a growing sphere (like how calls and generic noise are visualized)

Fixes for sessile animals

Upright bodies no longer become thin at the base when there are sessile feet (thanks Cody Beaver!)
Made 'sessile foot' limb connect to the torso seamlessly
Putting the ballistic mouth on top no longer crashes the game

Working on limb body parts

Fixed labels of small and large bas bags, and added the latter to the statistics file
Fixed the membrane positions for 'thin membrane for gliding', 'membrane from long finger for flying', 'small gas bag' and 'large gas bag' during animation
Added animation weights to 'adhesive' and 'sprawling foot with long toes' limb types
Improved animation weights for 'attractive vestigial wing' and 'cartilage fin'
Revised the 'venomous spines' model, so it works with animation this time

Small fixes for the legend when looking at soil statistics mid simulation

Centered it
Also show one for steepness
Remove it for climate zones

Cleanin up other UI

The top row button animations is now way faster, so you don't have to wait for (thanks Julenissen!)
The new soil statistic view no longer mixes overlaps with other views

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
30 Nov 2025Developer post
Patch v13.26
Working on body part loading Discovered that some limbs and accessories were saved incorrectly. This was hidden so far because the loading was ALSO incorrect, but will give problems in the future. From this patch onwards, some creatures saved with earlier versions of the game mig
Working on body part loading

Discovered that some limbs and accessories were saved incorrectly. This was hidden so far because the loading was ALSO incorrect, but will give problems in the future. From this patch onwards, some creatures saved with earlier versions of the game might load with other body parts than you remember.
Found a few situations where the assets were loaded multiple times, fixed that to reduce memory usage and decrease loading times

Finishing up parasitic fungus simulation

Increased chances of parasites finding a host
Parasites can now evolve into decomposers and back
Parasites can now evolve to specialize for another host
The population size updates now also support parasites, so you can see how successful your parasites are
Parasites species are now also visible on the habitat map
Made it possible to locate parasites in the world from the parasite species detail view
Exterminating fungus species now also exterminates parasites
Parasitic fungus models are now removed before reusing plant and animal models

Finishing up the extensions to the fungus editor

Reorganized fungus traits so the grouping in tabs makes more sense
Added mycelium explanation view
Designed mycelium icons
Designed trufflecap icon

Working on upright postures for alternative animal forms

Completely rewired how the game stores upright animals, so you can now have mix vertical and horizontal animals within a species
The horizontal/vertical switch now also works for juveniles, so you can have vertical juveniles with horizontal adults and vice versa
Similar to horizontal animals, torso slots that have limbs attached can no longer be moved around, preventing various glitches

Working on limb body parts

Added animation weights to 'fast two-toed runner', 'clawed, walking on toes', 'mountain climbing hoof' and the redesigned 'fast runner on toes' limb types, so they no longer appear invisible in game
Improved the feathered glider model so it works better with upright animals (thanks Cody Beaver!)
For the feathered glider, removed the feathered skin requirement
Removed various unused limbs so the animals cannot evolve them anymore (thanks viciouslandshark!)

Misc

Fixed incorrect climate zones directly after placing a volcano (thanks Olly Harrison!)
Added labels to icons in species detail view
When exterminating plants and fungi, now also exterminate plants and fungi inside or stuck to animals

I often forget to read comments below release notes, so if you have questions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
22 Nov 2025Developer post
Patch v13.23 (beta only)
Simulation fixes I think I finally figured out how to prevent sessile feet on the side. This bug caused numerous problems, like plants multiplying, corrupt saves and missing models in the species list view. Added steepness of the terrain and how limbs differ in what steepness the
Simulation fixes

I think I finally figured out how to prevent sessile feet on the side. This bug caused numerous problems, like plants multiplying, corrupt saves and missing models in the species list view.

Added steepness of the terrain and how limbs differ in what steepness they support

Also calculate the steepness underwater, as visible on the steepness map
Got the steepness map also working mid simulation
Added a maximum steepness statistic to limbs, editable in LimbStats.yaml
Changed the limb stats view to show this new steepness statistic in the animal editor
For the requirement panel when placing an animal, instead of just 'water', 'land' and 'steep', added various descriptions like 'mild slope' and 'cliff'
In the simulation, made sure animals cannot walk on terrain too steep for them, and also don't lay eggs there

Fixes for editing the terrain mid simulation

Fixed problem where the first drawing was always linked to an existing continent, instead of to a new one
Optimized drawing and moving continents (most noticeable when moving continents mid simulation)

Fixes for drawing statistics mid simulation

Prevented negative edit circle sizes (thanks azul1462!)
When drawing manual stats, prevented the colors always snapping back to the terrain colors (thanks azul1462!)
Set the initial value of the slider to 0.5, and made sure this reflects the actual initial value when painting
Fixed the slider snapping to incorrect values after releasing the mouse button
Fixed the draw tool sometimes missing the tile exactly in the middle of the circle
Optimization: decreased the time the game hangs after drawing statistics

Polishing upright animals in the animal editor

Designed horizontal/vertical toggle icons
Redesigned the general animal traits view, so the horizontal/vertical toggle fits better
Made all changes to the torso shape (diameter, displacement) less extreme when switching to the upright form
When switching, also update the mount point indicator positions and sizes
Fixed problem that bodyparts on the front ended up on the back when switching posture
Fixed problem where some body parts that ended up inside the torso when switching posture were not removed, while others that did not end up inside were (thanks PlayerDJNB!)
For body parts that base their appearance based on position, made sure upright animals now always show the correct model

Working on limbs

Fixed incorrect evolution tree lines going out of frame in some cases
Added parachute like wings to the arthropod limb tree
Improved the kangaroo legs models to better fit upright postures

I often forget to read comments below release notes, so if you have questions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
15 Nov 2025Developer post
Patch v13.22 (beta only)
Simulation fixes Prevented another way the sessile feet could evolve to be on the side. This bug causes numerous problems, like plants multiplying, corrupt saves and missing models in the species list view (thanks azul1462, TaterTot, MisterLiteralRandomGuy!) EDIT: hmm I just enco
Simulation fixes

Prevented another way the sessile feet could evolve to be on the side. This bug causes numerous problems, like plants multiplying, corrupt saves and missing models in the species list view (thanks azul1462, TaterTot, MisterLiteralRandomGuy!) EDIT: hmm I just encountered this problem again, still not fully fixed
Fixed sessile animal babies moving around (thanks ultraneongodpet, Jupiter Hater!)

Working on new limb body parts

Added a new gliding limb as intermediary step between insect limbs and insect wings
Remodeled the pterodactyl wings to be more impressive and closer to reality
Added top and back models for the exisitng gas bag body part
Added second larger gas bag body part
Fixed forcipule bodypart (was pointing the wrong way)
Improved the hitboxes for various limbs, so it's easier to (re)move them

Terrain editor fixes

When hovering multiple continents, only the smallest one now lights up (thanks Tatertot, Col. caboose!)
When hovering a contintent with a small map size in the planet editor, it now highlights correctly
When drawing new land mid simulation with a small map size, it now shows up at the correct position, with a size matching the brush size
Drawing outside of the map mid simulation no longer causes terrain in the exact middle
When toggling rings, the stats are now always updated correctly
Fixed the black maps that sometimes showed when editing terrain mid simulation
Fixed drawing mid simulation no longer being possible after changing the elevation of a continent

Soil statistic fixes

Added nutrients to the soil statistics in the world, including for the first time the option to paint nutrients
Got the wild fire risk map to work mid simulation
Fixed the wrong slider showing when looking at the wildfire risk in the planet editor
Your changes to manual statistics in the planet editor are now actually used in the simulation (thanks azul1462!)
You no longer lose all your manual statistic changes in the planet editor when switching to the planet or disaster tabs
Fixed softness/rockiness being inverted in some views
Fixed polar regions often being black instead of white when looking at the climate zones mid simulation
Fixed volcano eruption not updating the soil stats (thanks lin!)

Improving terrain editor audio

In the planet editor, the sound effects when editing terrain now match your cursor movements more closely.
The terrain editing sound effects now stop less abruptly
I often forget to read comments below release notes, so if you have questions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post
08 Nov 2025Developer post
Patch v13.21 (beta only)
Simulation fixes Fixed aquatic animal babies being stuck in the ground (thanks Hexadexx, Enzo Ramos Henrique, Ultraneongodpet, Kingdragon2026, Col. Caboose, bashclark1004, azul1462!) Fixed limbs mutating into sessile feet on the side, which the game cannot display (thanks AnniJPG
Simulation fixes

Fixed aquatic animal babies being stuck in the ground (thanks Hexadexx, Enzo Ramos Henrique, Ultraneongodpet, Kingdragon2026, Col. Caboose, bashclark1004, azul1462!)
Fixed limbs mutating into sessile feet on the side, which the game cannot display (thanks AnniJPG!)
Sped up time skips by removing excessive logs

Working on new limbs

Redesigned the limb stats view in the animal editor to match other stats view, including a place for a description
Added bird leg with two toes, inspired by ostriches
Added sprawling leg with long pointy nails, inspired by lizards
Improved model for the fast, digitigrade leg (as used by the milk bug)
Removed incorrect option to put new limbs on top and on the tail, where they looked like the starter fin
Added all new body parts to the .yaml files containing the statistics, so they can be tweaked
Removed that pressing D in the animal editor removes debug functionality, showing the hopping arthropod leg (thanks Abban!)

Fixes for the terrain editor

Made a start adding support for smaller map sizes: drawing in the planet editor seems to be working (thank azul1462, Jupiter hater, Col. caboose!)
When changing the terrain mid simulatiion, all soil statistics should now be correctly updated (thanks Cody Beaver!)
When you have manual changes turned on, and you change the terrain mid simulation, it will silently toggle back to non-manual changes to be able to recalculate what tiles are aquatic

Early balancing (much more to come later)

Made sure the new filter feeder mouths only filter feed and also gave them more descriptive names (thanks Alan!)
Made default moisture and temperature settings less extreme, so new players don't start with a difficult sandbox (thanks Sealous!)

Misc

As scenarios are not available yet, temporarily removed the requirement to complete at least one before the sandbox is available
I often forget to read comments below release notes, so if you have questions or bug reports, feel free to reach out via the Steam forums or [email protected].
Original post

Updates & announcements

To celebrate making it until here I (the dev Wessel Stoop) will be present in the chat tonight at 1900h UTC (2100h CEST, 1200h PDT, 1500h EDT)! Come watch the stream with me at twitch.tv/wesselstoop

Balancing and fixes for animals

Balancing and fixes for plants

Working on the weight system

Introduced savefile format 16

Various little editor fixes

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Balancing and fixes for plants

Balancing and fixes for animals

Fixes for custom terrain

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Working on land animal evolution

Other changes to the simulation

Improvements for the cladogram

Plant editor fixes

Animal editor fixes

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

More work on the project to make the game easier to understand

Redesigned the ready/discard buttons in all editors

Fixes for the new cladogram

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

A completely new cladogram view

UI mutation fixes

Introducing the next version save file format

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Major simulation change

Various changes to make the simulation easier to understand

Animation fixes

Fixes for terrain textures

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Overhauled optimization mechanism that decides which 3D models to show

Changes to animal mutation

Made it easier to keep your species alive

Started a project aimed at making the simulation easier to understand

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Completely overhauled how species are detected

Optimization

Fixes for sessile and/or upright animals

Improving behavior of keyboard controls

Discovered and fixed two causes of corrupt save files

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Fixes for juveniles and the red torso length handle in the animal editor

Various fixes for volcanoes

Fixed various unlocking mechanics

Fixes for the sandbox

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Improved upright bipeds

Other animation improvements

Fixes for seasons

Fixing terrain height bugs

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Resurrected the scenarios

Resurrected the daily challenge

Fixes for small map sizes

Polishing the walking animation

Fixes for upright animals

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

Reintroduced the 'randomize all' button

Polishing walking animations

Fixes for upright/sessile animals

Misc

I often forget to read comments below release notes, so if you have questions, suggestions or bug reports, feel free to reach out via the Steam forums or [email protected].

More work on animation

Working on limb body parts

Fixes for seasons in the planet editor

Other planet editor fixes

Small UI fixes

Sessile animal fixes