Press Esc and enter one of the following codes and click on "Back" button:
Win scenario: Triumph
Lose scenario: Succumb
Full ammo: Plethora
Stealth mode: Occultation
Invincible sarge: Invulnerable
Teleport sarge: Telekinetic
Enable explosions, opponent view, invincible sarge: Kahuna
Toggle opponent view: Omnisicient
Toggle right button explosion: Pyromancer
Full air support: Aeroballistics
Opponents paused: Paralysis