When the Copyright screen appears, press and hold Left and A until the screen disappears. When the Williams screen appears, press and hold Right and B until the screen disappears. When the "Knowledge is Power" screen appears, press and hold X and Y until Smoke walks across the screen. You can now access Smoke on the character select screen.
SOUND TEST
On the screen, press A, Y, B, X.
KOOL STUFF
On the Title screen, when Start Game/Options appears, press Up, Up, Down, Down, Left, Right, A, B and A. If you've entered the code in correctly, a new option will appear called "Kool Stuff."
KOOLER STUFF
On the Start Game/Options screen, press Select, A, B, Right, Left, Down, Down, Up, Up.
TOURNAMENT MODE
On the Start Game/Options screen, hold the L and R Buttons, then press Start.
SCOTTS STUFF
On the Start Game/Options screen, press X, B, A, Y, Up, Left, Down, Right, Down.
STEALTH SELECT
On the "Character Select" screen, rotate the controller counter-clockwise quickly, then press the Select button.
RANDOM SELECT
Press Up and Start on the Character Select screen.