OMG, this game is so freakin' beastly.. I dont own the game, but I've played it at my friend's house on his 360. Incredible game, better than Halo 2, imo.
It is a great game. The use of cover in this game is fun and easy. All you have to do is hit the A button to move from object to object to find cover from the enemy. My favorite part is chainsaw bannonet (sp?) where you cut through the ememies heads.