Type "!throw me a frickin bone here" during game play to enable cheat mode. Then, activate the following cheats by entering the corresponding codes:

CHEAT FUNCTION - CHEAT CODE
Mission skip - !cut to the chase
Debug mode - !rate me
Mission failed - !the meek
Disable tan AI - !oh behave
Enable tan AI - !mojo
Unit receives three bombing airstrikes - !heavenly glory
Unit receives three napalm airstrikes - !this one goes to eleven
Unit receives three recons - !peep show
Unit receives three paratroopers - !johnny ricco
Unit receives nine blue disguises - !i woke up this morning
Unit receives nine gray disguises - !incognito
Unit receives nine tan disguises - !no sunblock
Unit receives flak jacket - !whistle and flute
Unit receives unlimited ammo sniper rifle - !yippee!!!
Unit receives unlimited air attack - !roody-pooh
Unit receives unlimited plastic mending kit - !florence
Unlimited bazooka - !i like to keep this handy
Unlimited flamethrower - !patty melt
Unlimited grenades - !you want some
Vulcan machine gun - !hello neo
Minesweeper - !i got two words for ya...
30 mines - !sprinkles
Unit on fire - !disco inferno
Extinguishes fire - !disco is dead
Large explosion - !italian job
Teleport unit to pointer location - !door
Faster soldiers - !pump me up
Kill selected units - !time for bed
Random item/effect [Note 1] - !mona lisa
Remove disguises - !let me down
Display programmer message - !when all else fails...
Display programmer message - !vic fontaine
Invincibility for all units - !captain scarlet
Invincibility disabled - !only human
Small gun (use unknown) in item box - !here's a lockpick...
Small gun (use unknown) in item box - !penny

Note 1: A small gun may also appear in the item box. Its use is unknown.