At the Title screen, press Up, Up, Down, Down, Left, Left, Right, Right. If done correctly, the announcer will say Outstanding. Press Start to go to the Main Menu, move to Options and press L + R.
Play as Goro
Enter the code above for the Cheat Menu. At the Cheat Menu, select Hidden and choose Shinnok with Block + Run.
Play as Noob
Enter the code above for the Cheat Menu. At the Cheat Menu, select Hidden and choose Reiko with Block + Run.
Play as Sektor
Enter the code above for the Cheat Menu. At the Cheat Menu, select Hidden and choose Cyrax with Block + Run.