Archean

Archean is an engineering sandbox and space simulation where you build vehicles, spacecraft and other machines, then rely on their actual shape, wiring and programming to make them work. It simulates aerodynamics, orbital mechanics, fluids and electricity, with no unlock tree or hidden stats. You build in first person directly in the world, including on unfinished structures, rather than using a separate editor.

Build and test machines

Aerodynamics are calculated from the shape of your creation, without special wing blocks. Lift, drag, stalls, stability and control authority all depend on its design. Air and water use the same physics, so designs can work as planes, boats, submarines or hydrofoils. You can also build re-entry vehicles.

Machines use power, fuel, fluids, sensors and thrust. Connect their systems as you choose, then program them in XenonCode, the in-game programming language, or use the visual node editor. You can write and debug systems such as autopilots, launch sequencers, docking computers and mining rigs. A built-in cooperative editor includes syntax highlighting and multi-cursor support.

Explore a full-scale world

The game takes place on a full-scale young Earth with real topography. The Moon appears large in the sky, and the only living things are green plants; you are the planet’s first engineer. Planets are Earth-sized and separated by real distances, with no fixed map limit. You can walk across their spherical surfaces in first person and move seamlessly without loading screens or predefined paths.

Orbital mechanics run in real time, and planets rotate on tilted axes as they orbit the sun. The day-night cycle follows that motion, so dawn comes when the ground turns into sunlight. There is no speed limit: you can accelerate to 0.99c, but you must handle slowing down. Full n-body physics is available through a configuration setting.

Build, pressurize and survive

Cabins must hold pressure or leak. The game checks compartments voxel by voxel for airtightness, and spacecraft, submarines and airships must pass that test. You can walk through your creation, from its reactor room to its cockpit.

Electricity includes low- and high-voltage systems, with relays, junctions and converters for designing a grid. Thermodynamics and plumbing are also part of the engineering. Damage is physical rather than represented by a health bar: for example, a damaged wing loses lift and gains drag, which can make a plane pull to one side. You can engineer artificial gravity by accelerating at a steady 1 g or spinning a station, with Coriolis effects included.

Gather or create

Adventure mode begins with you on a planet with only your bare hands. You scan for ore, dig it up, crush it and craft it into parts. Creative mode gives you everything from the start. The game also includes explosions and destruction, custom dashboards and HUDs, and fully ray-traced rendering.

Play and mod

You can play solo, with friends or on public servers. Each server sets its own rules, star systems and mods. Star systems are configured with values such as mass in kilograms, orbits in meters and atmospheric composition by mole fraction. The default Moon orbits at geosynchronous distance; editing the configuration can instead create the present-day solar system or a fictional one.

You can create mods from inside the game, model components in Blender with the official plugin, and script their behavior in XenonCode, including screens, animations and ports. A YAML file makes a component craftable, and each server chooses which mods to run.