Code                Result
please giveall      All weapons    
Please fly          Fly Mode
Please ghost        No Clipping
Please giveall      All items
Please god          God mode
please invisible    Invisibility
Please killall      All enemys dead
Please open         All doors open
Please refreash     Max health
Please killall      Kill all enemies    
Please tellal       All data available in NETRICSA l  

Cheat Mode Alternate:
Press F1 to bring up the console window. Now type one of the below codes,
press Enter, then press F1 to activate it.

Code           Effect  
cht_bGod       God mode  
cht_bGiveAll   All weapons   
cht_bRefresh   Full health  

cht_bGhost     No clipping   
cht_bInvisible Invisibility   
cht_bFly       Flight mode 

Difficult levels:
Enter one of the below numbers to set the difficulty level.

0: Easy 
1: Normal 
2: Hard 
3: Serious   

Demo Version Cheats

Cheat Mode:
Press ~ at the main menu (the one with the single player and demo options)
to bring up the console window. Then enter one of the following codes.

Code                                 Effect     
ListSymbols()                        Display console commands   
gam_afDamageStrength= 0.0, 1.0, 2.0  Change damage from enemies in indicated difficulty level (1.0 is default).    
gam_afAmmoQuantity= 0.0, 1.0, 2.0    Change ammunition quantity in indicated difficulty level (1.0 is default).    
gam_afEnemyMovementSpeed= 0.0, 1.0, 2.0 Change enemy movement speed (1.0 is default)    
gam_afEnemyAttackSpeed= 0.0, 1.0, 2.0   Change enemy attack speed (1.0 is default) 

Hints

Master Strategies:
When surrounded by thousands of enemies strafe around them to get them all
in one lump. then blast the lump.

When facing a bull or Krell skeleton use the double barrel shotgun and
shoot them just after you’ve sidestepped.

Thanks to Revolution readers Dr. Seuss, Sam and Ghostmaker!