Cheat Menu
Go to the main menu and HOLD L + B + R and then release B, R, L.
Unlock Mothership Arena
To unlock the mothership arena, beat adventure mode with mecha Godzilla on any difficulty setting.
Unlock Pictures In Picture Gallery
To unlock pictures in the Gallery, you must play through Adventure Mode on the Medium or Hard difficulty setting. Some buildings that you destroy will reveal Silver Atari symbols. Pick these up to unlock a picture.
Get Gigan
Beat Adventure mode with Angilas.
Get King Ghidorah
Beat Adventure mode with Megalon.
Get Destroyah
Beat Adventure mode with Godzilla (Millennium).
Get Rodan
Beat Adventure mode with Gigan.
Get Mecha-King Ghidorah
Beat Adventure mode with King Ghidorah.
Get Mechagodzilla
Beat Adventure mode with Rodan.
Get Orga
Beat adventure mode using all characters then beat the adventure mode one more time using Godzilla 2000.
Extension to cheat menu
All Monsters: 209697
All Monsters Are Invisiable: 600225
All Players Are Small: 154974
All Players Deal Quadruple Damage: 817683
All Players Take No Damage: 569248
Black and White Mode: 860475
Boxing Ring: 440499
Constant Energy for Player One: 778393
Constant Energy for Player Two: 881557
Constant Energy for Player Three: 597558
Constant Energy for Player Four: 218967
Destoroyah: 352117
Disable HUD: 880460
Display Game Version Number at Option Menu: 097401
Cheat menu and various cheats
At the main menu highlight "Versus" and in order press and hold L, B, R, and then in orfer release B,R,L. If done correctly, a cheat menu will appear. Enter the following codes to unlock these cheats. If you entered the correct code, Godzilla will roar.
Here are some cheats:
12 Contnues in Adventrue Mode: 548319
Add A.I. Player to Melee: 154974
All Cities: 107504
All Cities and All Monsters: 863768
All gallery items: 962129
Twelve Continues In Adventure Mode
Enter 548319 at the cheat menu screen.
Technicolor Mode
Enter 394804 at the cheat menu screen.
Players' Health Regenerates
Enter 597378 at the cheat menu screen.