What Archean is
Archean is an engineering sandbox and space sim where nothing is unlocked for you. There is no tech tree, no wing blocks, no hidden stats. You gather ore, crush it, craft parts, and build vehicles directly in the world in first person, standing on the half-finished wing while you work. Aerodynamics, orbital mechanics, fluids and electricity are all computed from the actual shape and wiring of what you built. If your plane flies, it is because you built a plane that flies. A wing that dips underwater becomes a hydrofoil, so planes, boats, submarines and re-entry vehicles all follow the same rules with different shapes.
Every build is a real machine: power, fuel, fluids, sensors, thrust. You hook them up however you want, then write the behavior yourself in XenonCode, the built-in programming language, or wire it up in the visual node editor. Autopilots, launch sequencers, docking computers and mining rigs are all yours to write and debug. Damage works the same way — a broken wing sheds lift and gains drag, so you end up wrestling a plane that pulls to one side instead of reading a health bar.
Playing together
You can play solo, with friends, or on public servers, and each server sets its own rules, star systems and mods. Because orbital mechanics run in real time with no speed limit, two players can dock at a shared station while both are moving around the planet at orbital velocity. Planets are real-sized and set at real distances, so there is no map edge to run into.
Splitting the work suits co-op well: one person scans and digs ore and runs the crafting, another designs the airframe and wiring, another writes the XenonCode for the autopilot or the mining rig. Pressurization is checked voxel by voxel, so someone has to crawl through the hull and find the leak. Servers choose which mods they run, and mods can be created from inside the game — model a component, script it in XenonCode, drop in a YAML file to make it craftable.
Before you start
Adventure mode begins with bare hands on a young Earth: scan for ore, dig it, crush it, craft it, and every part of your ship started as a rock somewhere. Creative mode gives you everything from the start if you would rather skip straight to engineering. The game is in Early Access and is built by a team of two, so expect things to change.
Be ready for real physics rather than arcade handling. There is no artificial gravity block — you get weight by burning at a steady 1 g or spinning a station and living inside the ring, wobble included. Day and night come from the planet actually rotating with axial tilt, so a solar farm makes you care about how long a rotation takes. There are no loading screens, no skyboxes and no invisible walls, and the whole thing is fully ray-traced.