100 Nazi Scalps is a simple, cartoonish shooter that's incredibly addicting. Why? Because the premise of the game is to kill and scalp as many Nazis as possible. Yeah, it's just as fun as it sounds. It's also free right now.
The setting is World War II and you were sent to the war to kill Nazis. And that's exactly what you do. Gameplay is simple, you can only move backwards or forwards (and crouch) and you tap one button to shoot your weapon and tap the other button to knife your enemy (for scalping purposes only).
It's actually a pretty hard game because them Nazis are equipped with heavy duty firepower (which you can take after you kill them) and they attack from both directions. I've already died multiple times in the second level (6 levels total).
Other than that, it's just as fun as you would think. Best part is that this ridiculously silly game is free right now (it's usually $0.99). [iTunes]