G-Nome

At the Mission computer press ctrl+F1 .
           
Then You can enter one or more of the following codes. 
All the codes are case sensitive !!! Correct codes will
be confirmed by a beep. 

Here are the codes:

            
Redtop Trod       - Select all single player missions from the mission 
                    Menu.
Half Libel        - Activates Teleport key.
Had A Nude On     - Activates Invincibility key.
Brass Clue        - Activates Amunition Key.
Mother Mourn Us   - Changes mountain on mission 1-5 to Mt. Rushmore 
                    with programers faces.
Chaste Coed       - View the end video sequences.
Rotted Drop       - Activates Destroy Target.
Horny Elk Leer    - Activates all targets on radar key.
O'Sarge           - Gives Seargeant in training missions an Irish accent.
Swiss Throat      - Changes Citadel building into 7th level headquarters.
RANGE GOES GORY   - All Levels, and lots of other stuff
DUNK IT HERE      - Recording Session Outtakes
OH NO! LESS JAPAN - Activates Ion-Strike Key
A Scramble On     - Let's you take screen shots by pressing 
                    SHIFT-CTRL-RIGHT CLICK.
            
In-Game-Keys :
            
 CTRL+I - Activates Invinciblity
 CTRL+Z - Refills ammo
 CTRL+F - Destroy current target
 CTRL+B - Teleport Behind Target
 CTRL+P - All targets on radar
            

Photo Gallery 

Type "Swiss Throat" in the cheat code box and it changes the 
Citadel building in mission 2-6 to 7th Level Headquarters and 
inside are the pictures of the programers. Hit TAB to cycle 
through them. 

Pick a Ship 

If you use a gashr on any occupied ship, the pilot will come out. 
If you go into its ship, it's yours.