Halo 3: ODST is objective-based... objectives sort of like Star Wars Battlefront 2, only much better than the ones in that game xD. You aren't a super soldier spartan, just a shock trooper who has to do missions you'd find normal troops doing. Like setting detonators on a bridge to eliminate Covenant(almost said Combine, lol... been playing HL2 too much) soldiers. You won't be faced against huge over-powered mobs as much as Master Chief, and if you do, it'll probably be with a squadron. I think it is going to be the best game ever.