All Gallery Items:
Press Square, Down, L2, Down, L1, Square, Up, Square, Down, Down.

Open all levels:
Press Down, L2, Up, L1, Square, Down, Down, Down, Down, Up.

4 bonus door keys:
Press Square, L2, Down, L1, L1, Up, Square, Down, Up, Down.

Extra 10 Magic Pickups:
Press L1, Down, L1, L2, Square, Down, Up, Down, Up (2).

Extra Life:
Press Up, Down, Square, L2, L1, Down, Up, Down (2), Up.