Planetbase - Planetbase is a strategy game where you guide a group of space settlers trying to establish an outpost in a remote planet.
Aven Colony - Colonize an Alien World
RimWorld - RimWorld - A sci-fi colony sim driven by an intelligent AI storyteller.
Dwarf Fortress - Dwarf Fortress is a single-player fantasy game with two modes: fortress and adventure.
Spacebase DF-9 - Mine asteroids, discover derelicts, and deal with the tribulations of our distant future: Meteor impacts! Explosive decompression! Unbearable loneliness!
Startopia - Micromanage a network of space stations to rebuild them into a thriving community.