Everyone was shocked to find out that zombies exist. They come from out of nowhere and now most of your friends are zombies. Their numbers are increasing each time they kill someone, but you aren't ready to become one of them. You grab your gun and stared shooting. The idea here is to survive a zombie onslaught. There are different kinds of zombie and they are introduce as you move from one level to another. You earn money from every zombie you kill. You can use the money to buy some upgrades that you can use to fight the hordes of zombies.