Nazi Zombies is a gamemode in Call of Duty: World at War. Nazi Zombies Portable aims to recreate the Nazi Zombies experience from CoD: WaW into the Quake engine, making it playable on the Hand-Held PlayStation Portable Console and can be easily played on just about any computer out there.
Nazi Zombies consists of up to four people in survival against endless hordes and waves of "Nazi Zombies". Each wave the rounds get harder and harder, and you get points for barricading walls and killing zombies. You use the points to buy guns or you can spend them on the mystery box where you get a random gun in return.