Unlock ALL Modes and Characters:
At the Main menu press and hold A + B and push L, R, R, L, L, Up, Up, R. Enter the code again if it does not work the first time.

Unlock Team Battle Modes:
Complete Arcade mode as Heihachi to unlock the and Versus Team Battle options.

Unlock Alternate Costumes:
At the character Selection screen prompt press L, R, or Start.

Unlock Heihachi:
With ALL 9 characters complete the game and Heihachi will be the fighter after Hworang and Paul at the Character Selection screen.

Switch Fighters:
At the Versus screen in Tag Team mode press R.