Press [Punch] [Sense] [Punch] [Sense] [Punch] [Punch] [Crouch] [Sense] at the main menu. The sound of a click will confirm correct code entry. Then, press the following [Punch] [Sense] [Punch] [Sense] [Punch] [Punch] [Sense] [Crouch]. You will hear two clicks. After the second click, the "Level Select" options should now appear instead of the "Continue" option at the main menu. Also, a cheat menu that includes an "Invincibility" option will appear when game play is paused. This unlocks everything except the Strikes.