Various Cheats:

To give those little green plastic soldiers the edge, activate these cheats by hitting the Escape key and typing in the following codes.

INVULNERABLE Sarge becomes invulnerable
PLETHORA full ammo
SUCCUMB lose the scenario
TRIUMPH win the scenario
OMNISCIENT view all troops
PYROMANCER right button explosion
AEROBALLISTICS full air support
PARALYSIS foes pinned in place
TELEKINETIC teleport Sarge anywhere on map (must be in Scroll mode)
OCCULTATION Stealth mode (until Sarge shoots)
KAHUNA explosions, omniscient view, and invulnerability