WOW!
It's a great game. Everything was cool especially the secret 11th weapon. I found this one glitch/bug that I call "moonwalk mode". When I let a lot of zombies (about 8) beat up the fortress, i right-clicked the screen and clicked rewind. Then when it restarts, zombies are already on the screen. And when you play some zombies will walk in the air, backwards and they'll flash off and on agian.