War Gods

Enable Freeplay:
Hit C-Left, C-Left, Right, A, B, C-Up, C-Right at the title screen.
After, go to the options and highlight the "Continues" option.
Tap Left until the word "Freeplay" appears.

Select characters randomly:
Hit Up + Start at the character selection screen,

Unlock Exor to play:
Go to the fighter selection screen and press the following button
combination: Left, Down, Down, Right, Left, Up, Left, Up, Right,
Down after select any character.

Unlock Grox to play:
Go to the fighter selection screen and press the following button
combination: Down, Right, Left, Left, Up, Down, Right, Up, Left,
Left after select any character.

Cheat menu
Go to the screen when you see the "Midway Presents War Gods" text.
Quickly press Right, Right, Right, B, B, A, A.

You have to enter this code before the start and option menu
appear at the title screen. If the code is accepted, the screen
will flash. Now you have access to the following cheat options:
-Game timer
-Level select
-Player one skill
-Player two skill
-Easy fatalities: Enable this cheat and hit A + B + C-Top + C-Right
to perform fatality with any fighter.

Cheat mode in Japanese version
Hit Left, Left, Left, B, B, A, A at the title screen.