Select level
Press R2, left, right, R1, L1, up, down, L2 in the main menu.
Invincible
Press L2, square, L1, circle, r2, square, L1, circle in the main menu.
Unlimited ammunition
Press square, L1, R1, top, circle, L2, R2, below in the main menu.
Flying Chamber option
Click above, L1, below, R1, R2, below, L2, above in the main menu.
Activate FMV sequences in the gallery
Press circle, L2, left, R1, R2, right, L1 in the main menu.
See intermission sequences
Right press, circle, square (2), R1, R2, left, L2 in the main menu.
Debug information
Press Left, L1 (2), Right, R1 (2), Up, down in the main menu.