Wolfenstein 3D:
Successfully complete the game in single player campaign mode to unlock the original Wolfenstein 3D.

Hint: Peeking around corners:
Click and hold the Left Analog-stick while moving it left or right. The only problem is that you cannot shoot.

Hint Head shots:
Turn off the automatic aim option to get a good head shot. Otherwise, you will lock on to the enemy's body.

Hint: Multi-player mode: Airstrike:
A lieutenant can call in an airstrike by pressing Zoom, then pulling the trigger on where you want the bombs to drop. There is a ten second delay.

Hint: Multi-player mode: Medical kit:
A medic can help his teammates by switching to the medical kit. Press R to drop it