[Suicide Junkie]

Looks like an FPS.

I'm thinking some sort of strategy game might have been better.
You'd play as a System Lord; enslaving planets, building fleets and troops to send against the other system lords.
Pile troops though the stargate, and/or bring a fleet to blast things from low orbit.

Those pesky humans would send little sneaky raids every now and then to keep you on your toes, blowing up your shipyards, enticing your soldiers to defect, etc.