Macworld writes: "The title sort of explains it all. Open the game, choose one of three levels ("Alleyway", "Cemetery" or "Hospital"), choose a difficulty level ("Easy", "Normal" or "Hard") and begin shooting zombies as they duck out behind doorways, sewer grates, headstones, hallways, ceiling vents, etc. The zombies don't inflict damage to the player and can be shot or left alone, but you need to check your fire when innocent civilians duck out from behind objects. Hit enough civilians and the game ends. The higher levels afford you less breathing room as three slain civilians on the "Hard" setting end the game."