CS Zombies Battle (Unhacked Version)

Game Information
Because of an accident, the personnel of the biochemical laboratory all become zombies. You are in charge of the blockade of the laboratory to prevent zombies come out from laboratory. Headshot means more damage and higher score. After battle you can buy medicine bag, all kinds of ammo and more powerful guns. The game will become more and more difficult as the amount and type of zombies will increase! Wish you good luck!