Enter one of the following codes while the game is paused:
First pause the game and press: L2, R1, L1, R2, UP, DOWN, UP, DOWN, SELECT, SELECT. And it should say Invulnerability.
Level Select
Press Down(9), Up {See Note Below} Note: After entering this code, exit the game. Then at the bottom of the main menu there will be a new option called "Time To Kill". Select this new option, then press Left or Right to choose a level and press X to go to the level.
Intro Scene: Pause game, press select, up nine times, select, L1.
Victory Scene: Pause game, Select, up nine times, select, L2.
View Credits: Pause game, Select, up nine times, select, R1.
Make Duke Wear A Kilt:Pause game, Select, up nine times, select, R2