Hold Right and press B, C, B(2) at the main menu. Release Right and press A to display the debug menu.
Invincibility
Enable the "Debug mode" and "Level select" codes. Hold B and press Left, Right(2), Left at the level selection menu.
Level select
Enable the "Debug mode" code. Highlight the "Run Game" option on the debug menu, hold Left, and press B, C, B, C. Release Left and press A to display the level selection menu.
View FMV sequences
Hold C and press Right, Left at the options screen. Release C and enter the "Sound Test" option to access the "Cinema Sequences" selection.