G'day Rat Racers.
This patch contains changes that were intended to be released with the upcoming Online Mode patch intended to go live on the 24th October 2025. However, due to a particular emergency affecting not just Rattus Velocitas but a large number of games built with Unity, some bugfixes, balance changes and a new game mechanic are releasing early.
Below are the changes:
Upgraded UnityEngine to version 6000.0.58f2 (from 6000.0.38f1) to mitigate CVE-2025-59489. For the tech nerds, more details can be found here: https://unity.com/security/sept-2025-01 Please note previous versions of Rattus Velocitas may now be detected as malware by Windows Defender and other antivirus products in future due to this CVE affecting ALL unity game engine titles as old as version 2017.1
Introduced draughting; now it is possible to ride near or inside another racer's jetstream to get a minor increase in top speed! This can be stacked with boosts as well.
Note that CPU racers are intentionally not capable of draughting in any way, shape or form as they already have their own in-built "catch-up" system.
Fixed an issue that made Item drop RNG not work as intended. Certain items in particular ("INCOMING" constantly appearing on me, I'm looking at you) won't be as spammy.
Item Balance has been adjusted. Cheese was a bit too frequently obtainable. Missiles, while "scarce," almost always dropped as a multi-pickup (aka. more than 1 was obtained), making them too oppressive.
Cheese drop chance: 24% -> 22% (nerf)
Missile drop chance: 16% -> 18% (buff)
Missile multiple drop chance: 70% -> 30% (nerf)
Adjusted procgen for Item boxes and Dash Rings to be better spaced across the entire length of a given race course. NOTE: This change breaks replay playback completely on old replays; sorry about that. :(
Introduced a new "High quality water" setting. This will be disabled by default on pre-existing graphics configurations and can be turned on via the options menu. This adds high quality refractions to water present in Beach when enabled.
Fixed several issues with faked 3D audio effects in splitscreen races. This fixes the known issue "Sometimes sounds from despawned Missiles would linger in splitscreen after despawning"
Introduced speaker-based volume levelling for splitscreen races. Now if more than one player is sharing a stereo speaker, sound "heard" by both players will be properly mixed for only that speaker, rather than for every player. This should improve volume levelling across the board.
Made jetstream trails on racers more visually consistent at lower framerates.
Optimised environmental effects in Forest and Volcanic.
Optimised CPU performance in a number of places.
Made LOD more aggressive in Forest.
Fixed a LOD bias issue that lead to lower quality environment meshes than intended in some places.
Fixed a bug where new saves in tutorial mode accidentally affected random race environment selection when the game is running in attract mode.
Made the game window remain visible in the background when alt-tabbing; this fixes an issue where the Discord Overlay when enabled in some cases could cause Rattus Velocitas to minimise itself on game startup.
Made D3D11 the default graphics API on Windows. This was done due to the large number of startup crashes coming from AMD graphics card users. The game will now prompt on game startup in Steam if you would like to pick Vulkan as your preferred graphics API, unless you've told Steam to start with a specific launch configuration. NOTE: If you're using the "Reduce Latency" setting, this may result in a sharp decrease in performance; try disabling this in the options menu or using the Vulkan API if you have performance issues after installing this patch and didn't have any crash problems beforehand.
Added D3D12 as a launch configuration on Windows. NOTE: Highly experimental and may not start due to a bug with Unity. More on D3D12 in the next weekly report I'll be writing up soon.
Removed the Wayland mode launch configuration on Linux. This can be brought back via Steam launch options with -force-wayland
Added the OpenGL launch configuration on Linux. Equivalent to inserting -force-glcore in the Steam Launch Options.
Known issues:
Using "Reduce Latency" on Windows with D3D11 can reduce performance significantly. This is a Unity limitation that can't be worked around. A powerful CPU will still allow enabling this setting if your computer cannot run Vulkan properly.
Missiles occasionally emit a glitch trail when fired shortly after another missile despawned. This is entirely cosmetic and doesn't affect Missile operation.