To  use  the  cheats,  you  hit  Ctrl-Enter, type the appropriate
phrase  (all  lower-case;  the  cheats  are  case-sensitive), then hit
Enter.

Code                         Result 
the truth is out there       Unlimited Ammo 
fight the future             Replenish Current Ammo 
black oil                    Refuel 
trust no one                 God Mode 
i want to believe            No Crash 
this isnt happening          Heal 
ghostpit                     Invisible Plane 
i am the one                 Infinite Health