At the main menu, highlight "Versus" mode, then hold L + R + B. Release the button in this order: B, R, L. If done correctly, a white box will appear. Enter the following codes to activate the cheat function:

Code: Result:
696924 All characters (except Orga)
225133 Unlock Godzilla 2K
104332 Unlock Rodan
537084 Unlock Destoroyah
557456 Unlock Mecha King Ghidorah
616233 Unlock Gigan
131008 Unlock Mecha Godzilla
877467 Unlock King Ghidorah
480148 Unlock all cites
677251 P1 Unlimited Energy
435976 P2 Unlimited Energy
603696 P3 Unlimited Energy
291680 P4 Unlimited Energy
256806 Military On/Off
413403 No energy power-ups
562142 No health power-ups
134615 No Mothra power-ups
841720 No freeze tanks
119702 No rage power-ups
843901 P1 Damage-proof
706149 P2 Damage-proof
188522 P3 Damage-proof
286552 P4 Damage-proof
505634 All players Damage-proof
650867 P1 Power energy
492877 Slow Health regeneration
649640 P1 Rage Mode
122224 P2 Rage Mode
548053 P3 Rage Mode
451242 P4 Rage Mode
511012 P1 Qaud damage
815480 P2 Qaud damage
212454 P3 Qaud damage
286552 P4 Qaud damage
817683 All players Qaud damage
459113 P2 Invisible
316022 All monsters Invisible
986875 Tiny P1
971934 Tiny P2
895636 Tiny P3
795735 Tiny P4
174204 Tiny players
756287 Throwable buildings & objects
135984 Player Indicators On
112122 Indestructible buildings
760611 11 continues (Adventure Mode)
661334 Technicolor Mode
567980 Black and White Mode
443253 No Life & Energy bars
097401 Show Game version in Options
176542 Shows Credits