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• Ctrl : Fire, hold Control down to fire rapidly
•  ↑  ↓  : Move forwards/backwards
• ←→ : turn left/right
• Shift : hold while moving to run
• Alt : hold while using ← or → to strafe (move sidways)
• Space : Activate Switches, Open Doors etc...
• Enter : Shows the last message that appeared in the top left corner in the Screen, or to select something in the menu
• Tab : View the Map
• Esc : View menu (this can be used any time in the game, including at the title screen, and ending texture screen)