To play as Dr. Kiln:
At the Character Select screen hold the L button and press B, C-Left, C-Up, C-Right, C-Down, A.

To play as Sumo Santa:
At the Character Select screen, hold L and press A, C-Down, C-Right, C-Up, C-Left, B.

To play as the Energizer Bunny:
On a one player game, pick bad Mr. Frosty and before the level begins press A, B, A, B, B, B, A, Z, B, A, Z, Z, A, C-Left. Bad Mr. Frosty will explode and you'll be the Energizer Bunny!

Random Select:
Press R and L simultaneously at the Character Select screen for random fighter selection.

Stage Select:
When the Versus screen appears in 2-player mode, press any C-button to select a stage.

Change Colors:
Press C-Down - the character that is highlighted will be a different color.

Secret Options:
At the Character Select screen, hold L and press C-Up, C-Right, C-Left, C-Down, B, A, A. The screen will flash to confirm the code. Now press the B button to go back to the Title screen. Select Options, and check out the Secret Options....

Thanks to Revolution readers Richard Ballard, Coolman, Mingun Kim, David Gomez, and Junior Elizondo!