During gameplay, press [Ctrl][Enter], type in any of the following
 Codes, then press [Enter] again:

 the truth is out there - Unlimited ammo
 fight the future       - Replenish ammo
 trust no one           - Invincible
 black oil              - Refuel
 i want to believe      - No crash
 this isn't happening   - Heal
 ghostpit               - Invisible plane