Wolfenstein 3D

Move: Arrow keys
Run: Shift
Strafe: Alt + left/right arrow
Fire: Ctrl
Use / Open: Space
Weapon select: 1&ndash;4
Pause: P
Fullscreen: Use the player toolbar button

MS-DOS v1.4 (GOG) — Escape from Castle Wolfenstein and fight through all six episodes of Nazi-infested corridors.