The weapons need better placement in the hands. I saw the gun merge with the top of the helmet while peeking out of cover. Also, it could use some better sounds and the helmet needs to be a bit more rounded. Not pointy like Master Cheif's helmet in the first Halo game.
This has been Episode 55 of EvDowg's Stickling/C. Critisicm Moments.
EDIT: Talked all this over with Zorro.