Use arrow keys or WASD to move, point mouse to aim, and click to shoot. When you defeat a zombie, you gain money based on its power. You can also collect the money cases that spawn periodically to gain money. Press P to open and close the shop. Note that if you buy a life while you are at 3, you will not gain an extra life. Hotkeys for the guns are: 1- Pistol 2- Machine gun 3- Minigun 4- Sniper 5- Bullethose