They’ve officially labeled it pre-alpha.

Right now, it’s a basic simulator set in our solar system. They haven’t really added many gameplay elements yet: for example, they just added the ability of high g-forces/impact to destroy ships/cats (just disappear, no explosions, no incremental damage.) Fictional solar system, resources (money, xp/science, etc.), missions/objectives, etc. are still a ways off.

They’re currently testing a Steam-like game client that will allow game updates without manually reinstalling every time a new version is released, so I plan to at least wait for that.