Gratuitous Space Battles: Galactic Conquest Windows, Mac, Linux, Linux64 game

The galaxy you fight over has 52 different planets, with you in control of just one of them at the start of the campaign. You can play as any race from Gratuitous Space Battles, or it's expansion packs, and in your attempt to conquer the galaxy you will come up against enemy fleets from all the different races, including expansion pack races (if installed). The fleets you encounter will not be AI - designed, but they are the creations of other GSB players. In a cunning 'massively-singleplayer' system, GC will constantly download the fleet and ship designs of other players to fight as your opponents, whilst uploading some of your fleets to fight against everyone else. This way you will be constantly challenged and surprised by enemy tactics and ship designs.