From the same developer is another space based game called Space Invasion.

This one goes for the grander scale of space combat, with you as the commander of your own galactic empire, with a mission to conquer uncharter planets, found colonies and build squadrons for battle.

So if you prefer space RTS game rather than action style games then this will probably appeal more than Dark Orbit does.

http://en.bigpoint.com/games/spaceinvasion/