Original concept but it could use alot of work. Like 'Flood' mode which would just pour creeps relentlessly at you causing you to die in a few seconds or 'Invisible' mode where you can't see the creeps! And I got the Immaculate badge ON MY FIRST TRY! It's so easy you've got to be retarded not to do it. Just build a pellet tower in the middle and it should take care of all of 'em.