and I personally like Xbox games better than comp games, but i think this would be a comp game.
I
think it would be better to play as a covenant, maybe a Arbiter.
Running through different planets on missions for the Covenant, or
simply trying to survive. It wouldnt even have to be a FPS,
although that would be cool. The game would work alot better as
KOTOR style play. I be this could all be made quite simply by a
video game maker. You probably could simply change audio and the
people in the actual KOTOR games 
Even though that would be illegal...