How to win in zombie mode.
Basically, choose "Facility", then wait by the window at the opposite side of the room from the stairs. Let a zombie through the window, then headshot it with the knife. Repair the window and repeat. When you have around 7000 points, or less and a Fire Sale, wait until there is only one zombie left in the current round. Throw a knife at him to weaken him, then remove the first barrier (honestly it's a sofa, could just climb over it without paying 5000 points), run up the stairs and go to the mystery box. If the first weapon sucks, keep trying. Assuming you get a useful weapon (any automatic), camp by the box and kill as they come through the door or window to your left. Using this tactic I got to round 12. Good luck and aim for the bloody head.
Added by: Guest Jun 14th 2011, ID#15826