Use the following method to enable cheat codes in the game.
1) Start the game and create a profile. Do NOT use the "DEFAULT" profile. Save the game at least once after creating your profile.
2) Open up the .ini file for your profile using Notepad. You can find this file in the \profiles\ dir of where you installed the game.. The ini file is named the same as the profile you created in step #1.
3) Look for empty keys to bind commands to. These may look like "F1=", "F2=", etc. Add any of the following cheat commands to the end of these blank bindings.
Code - Result
Invisible 1 - Invisibility
Invincible 1 - God Mode
ammo - Give Ammo
fly - Fly Mode
walk - Walk Mode
playersonly - Freeze Enemies
health - Give Health
killpawns - Kill All Enemies
ghost - No Clipping Mode
OPSAT - Unknown Effect
Once you bind the commands, it will look something like:
Make sure there are no spaces between the "=" and the command.
4) Save the file and restart the game, selecting your profile. Now, while playing you can use the keys that you set up in the file. Using the example above, pressing "F2" would give you god mode.