Great game - However
As I said, great game, had alot of fun playing this, very well thought out about the different types of zombies, as well as the aray of weapons, but just wanted to point out that there's a bug when going from the Uzi/M4/AK to the Shotgun(haven't tried with the sawn-off yet, but I wouldn't be surprised if this worked on it too) or Barret:
If you hold down the mouse button to go 'full-auto' with the Uzi, M4, or the AK, and then press spacebar while holding the mouse button down, you'll switch to the shotgun/Barret and fire all of it's rounds ala 'full-auto' just like the Uzi/M4/AK - makes for crazy crowd control. Just wanted to point that out.