Greetings surveyors!

I’m excited to reveal the trailer for Side D, the first free content expansion for Periphery Synthetic. The EP launched with three musical worlds to explore as you upgrade your abilities and reveal their secrets. The upcoming expansion significantly expands your journey with two new worlds, complete with new abilities and secrets to unlock! Continue reading for the trailer and major details about the changes arriving in 2025.

Watch the trailer

About the trailer

The trailer begins with flythroughs of familiar locations across the Alpha Periphery system. They are regularly interjected by title cards which actively describe the gameplay. My intent with this first section was to reintroduce folks to the EP while showcasing the diversity of its explorable environments. Compared to previous trailers, I’m unafraid to share some surprises here, such as the exosphere above the desert planet.

This is also the first trailer which I’ve included environmental sounds and audio descriptions for each scene. These were created quite simply with OBS, Notepad, and NVDA, alternating succinctly between the Microsoft David and Zira voices. For future trailers, I would love to continue including these features to enhance their accessibility.

The new stuff

The middle sections finally reveal the new worlds arriving in the expansion: Alpha Periphery D2 and The Interstice. This pre-release footage demonstrates that their development is quite far along, with thoughtful displays of terrain generation, color selections, and particle effects. However, please beware that it may not be representative of them upon release.

The trailer concludes with the portraits of each world which appear on the title screen of the EP. Newly added to the exosolar family is the green silhouette of the lichen sphere. I personally enjoy punctuating each trailer with these because it emphasizes how they are places that theoretically exist and can be touched. Notably, this excludes The Interstice, which is more of a metaphor than anything else.

About the expansion

The main objective of Side D is to wrap up all of the loose ends of Periphery Synthetic that began in a notebook in early 2022. This includes the last of the planned abilities and story beats. However, it leaves open new possibilities for future expansions and smaller content updates.

Key features

Overall, the expansion nearly doubles the size of the EP:

• Two new explorable worlds.
• Two new unlockable abilities with seven upgrade paths.
• Three new upgrade paths for existing abilities.
• Higher maximum levels for four upgrade paths.
• Two dozen new pieces of narrative text.
• Five new achievements to unlock.
• Rebalanced upgrade costs.

Alpha Periphery D2

The first new world arriving with Side D is one that I have previously discussed at length. With a surface gravity of about half of Earth's, Alpha Periphery D2 occupies a unique niche within the system. Throughout its brisk daylight cycle, the moss which covers its surface morphs through familiar seasons in color and form.

Falling with style

With the new xenotechnology found on its surface, a new gliding ability can be unlocked. By pressing any direction while falling, it allows changes in direction without using the thrusters. When fully upgraded, essentially any fall can be broken into a smooth flight. This is paired with new upgrades which increase the maximum velocity and reduce drag during flight.

This new ability synergizes pretty well with how the collectables are placed on this world. Instead of gluing them to the ever-changing surface, they remain fixed in the air at the terrain’s highest point. These aerial materials offer a fresh challenge for folks who enjoy jumping and flying.

Revealing the architects

However, my best-kept secret with Alpha Periphery D2 has been its surface water. It represents quite an upgrade to the underlying engine and movement physics. Throughout the world, you may encounter shallow areas in the moss, which expose its artificial crust. These areas are pocketed with reservoirs of heavy water which sustain the moss.

Perhaps these pools lead somewhere when fully examined? The artifacts found in these locations finally reveal the architects of the Alpha Periphery system. As if a laboratory to test their capabilities, it foreshadows the galactic protectors who The Pact must now face. With the history of the system now fully revealed, there are more possibilities to explore in future expansions.

Rebalancing the economy

A shortcoming of the EP at release was how it locked the materials for each upgrade to specific worlds. This forced folks to engage with content that they had no desire (or simply were not fully ready) to explore. Therefore, a major goal for the expansion is to make these materials more attainable through alternative means.

Yet another unique quality of Alpha Periphery D2 is how it contains every possible material to collect. For example, it is no longer required to explore the ocean floor of Alpha Periphery C, because its materials can be found on the surface here. Its atmosphere also contains the largest variety of elements that can be distilled. This is due to its unique role as the elemental incubator for the Alpha Periphery experiment.

Transmuting materials

Another frustration with the EP at release was the relative randomness of how materials are received. There can be points where there is little agency over which upgrades to select when a material isn’t appearing as expected. Often this can make the EP feel like an unnecessary chore.

The second new ability arriving in Side D allows materials to be transmuted from one to another using one of two new currencies. When an undesired material is collected, it can be broken down into its corresponding currency, from which related materials can be fused. To keep things fresh, there is even a slight chance for a critical success!

Downgrading abilities

This new ability is rounded out with the choice to downgrade (or fully uninstall) abilities. For example, the attractors ability can be downgraded to offer more challenge while collecting the aerial materials on Alpha Periphery D2. Or perhaps returning players might downgrade themselves to more quickly unlock the new abilities. With this expansion, all of these choices are now fully yours to make.

Adding fission and fusion also provides a unique opportunity to overhaul the material requirements for each upgrade. Although the overall costs have not changed, they have been realigned to play to the strengths of each world. Importantly, there is a greater balance of uses for each material, which has been carefully selected so that each upgrade path has a similar cost if transmuted from scratch.

The Interstice

Today I’m excited to share the biggest secret arriving in Side D: The Interstice. Quickly it’s revealed that the worlds of Alpha Periphery are interconnected by mysterious portals. However, these portals were handwaved away by a mere loading screen at release. The Interstice replaces these loading screens with a fully interactive sequence that explores this unseen dimension of spacetime.

A different mirror

The main purpose of The Interstice is to thread the worlds of Alpha Periphery together with a common element which holds a mirror to your personal journey. Being the first world that can be visited after Alpha Periphery B, it is intended to be visited early and often as the remaining worlds are discovered. Even with all the destinations discovered, it aims to be a fun place to revisit purposefully.

Graphically and mechanically, The Interstice is very much a non-Euclidean space. Best described as the inside of a torus, it functions similarly to the way the maze wraps in a game of Pac-Man. When moving through The Interstice, its terrain features grow more vertical as they get closer, evoking a disorienting psychedelic effect. Eventually the terrain wraps back onto itself into loops, as if walking along a Möbius strip.

As the apparatus is leveled up, the size and complexity of The Interstice evolves alongside it. While the first visit may be a short walk across a flat plain, subsequent visits reveal massive environments of ever-changing mountains and cliffs to navigate. And as this space opens up, it fills with caches and trinkets to collect, rewarding time spent off the most direct paths toward its thrumming exit.

Finding yourself

A key consideration for Periphery Synthetic was for players to feel free to insert their selves into its narrative. This is emphasized by the consistent use of the second person throughout its text, with vivid descriptions of emotions and sensory details. It has also been careful to avoid prescribing any personal details or history onto the main character, hiding them behind a shroud of memory loss.

As it expands, The Interstice regularly conveys perceptions which bridge the narrative gaps which identify the protagonist. Without spoiling the big reveal, they expound upon the true nature of the apparatus and its metaphorical relationship to the player. There are further insights that these could reveal about The Pact and Provenance One as well.

Coming in 2025

Beware! The price of Periphery Synthetic will increase to $5 USD when Side D is released. This is to reflect the new content and enhancements since the initial release. Thanks for understanding!

The wait to reveal these details over the past six months has seemed like an eternity to me. However, I wanted to be absolutely sure of the feasibility of its ambition, before making any promises that could not be kept. Yet, it has finally come to focus at this stage in development, where the only major remaining tasks are sound design, writing, and some polish.

To be clear: these are monumental tasks. I’m also strongly considering a break from the project during the month of February to prototype a new concept for Games for Blind Gamers 4. Therefore, the expansion is likely not arriving before the summer of next year. Despite this, I’ll continue to release a trickle of smaller hotfixes in parallel as needed.

I’m excited to share the release date with you soon. Thanks for reading!