Fight Jade:
Win one round using only low kicks in the match before the "?" round.

Fight Smoke:
Quickly press [F1] or [F2] when Dan Forden appears and says "Toasty!" on the Portal stage.

Unlimited credits:
Wait until the countdown at the continue screen begins. Press [F2] to start a two player game, then press [F1] while in the two player menu. After you defeat the player two you will continue the game at the place you left off without losing a credit.

Fight Noob Saibot:
Win 25 consecutive matches, then win the first round of the next match.

Debug mode:
Press [F10] at one of the logo screens to enter the options menu. Then, type DIP (case-sensitive) to display the debug switch menu. Activate the corresponding DIP switch to activate the corresponding effect.