In 2071 a newly opened mine on Mars becomes the site of a disappearance. A pioneer team goes in, stops reporting, and a second team of up to four follows them down a shaft that turns out to be ten miles deep.
Then the elevator fails.
What is down there
A subterranean world with dense jungle, weather and its own fauna — not a cave system with crystals, but an ecosystem with a food chain. The store page describes it as living and reactive, and the systems back that up: the base you inhabit decays because growth moves in, and infection is a state the world imposes on you.
Why it matters for play
The setting is not decoration. Three mechanics come directly out of it:
- The world reclaims. Vines, fungal growth and creeping organisms overtake structures you neglect. Your base is a maintenance task, not an achievement.
- Observation is the resource system. Studying how creatures interact with their environment produces materials and tools.
- Adaptation is a choice with a price. Mutation offers capability in exchange for something, and the alternative is to stay human and rely on tools.
What the mission actually asks for
The stated objective is not "escape". It is to find the pioneer team, then restore contact: an energy source has to be recovered and delivered to a printer and a signal booster, which is what turns a crashed expedition back into a working operation.
That framing matters for how the game reads. The base is not a tent you build and forget; it is a facility with power, and the progression loop runs through making it functional again. An AI assistant carries the tutorial weight and the scanning interface, which is why the first hour is mostly listening to it and pointing a scanner at things.
The two branches
The story page covers the mission, the AI assistant and the two endings the design implies: use science to stay human, or accept symbiosis. The biomes page covers what the underground is made of and how the environment itself becomes a hazard.