Level select:
Start the game without a memory card. Select campaign mode, choose Load Game, then enter P8H!H!P8P?H!? as a password.

Level passwords:
Level 02 - 4yh8h8pyp?h87
Level 03 - wyl8l8xqh?l8z
Level 04 - !yp5p5?qh?p8z
Level 05 - czt5t5hrf?t8z
Level 06 - kzx5v5prf?x8z
Level 07 - sz75z5xrf?78z
Level 08 - 6z?595?rf??8z
Level 09 - c6dvbvhsf9d9j
Level 10 - k6gvfrpsf9g9j
Level 11 - s6kvjrxcf9k9j