There should be direction facing... that is if u start moving in one direction u can't see behind u... this would be good since it mean u could sneak on a player with a melee weapon ^^
What I find so funny is that the monster are so retarded they can't walk in a straight line ^^ .... oh... btw... noice idea for a game... just gets repetitive.... maybe u could include fight scenes that use other old games like missile command or something ^^