Mortal Combat Cheater

Cheat                                                                              
Hold L2 press: square, down, up, L1, L1, up, square release L2 Unlock Sub-Zero     Effect   
Hold L2 press: square, up, L1, R1, left, right, square release L2  Unlock Scorpion
Unlock Mortal Kombat II Arcade

*Does not work for the PAL version of the game.* Enter this code while on the main menu screen. You should hear a sound if you entered it correctly.
Cheat                                                                                                           Effect
Hold the L2 Button down and press Square, Up, Down, Right, Left, R2 and Square Unlocks Mortal Kombat II Arcade in the Kontent section