This isn’t quite a game (yet), but an open-source generator for pulp sci-fi settings inspired by How to Host a Dungeon and the Dwarf Fortress world generator. You can view an animated description of the setting’s evolution, pause at any time, and export a detailed description of the world as a text file. To try it out, launch the program and keep hitting space to advance, or press R to enter auto-advance mode and come back later. You can move around with the arrow keys and see information about planets by putting the cursor over them.
Download (450 kB jar file).
Example Text Output
GitHub Page (source!)