Level select:
Start the game, do not use a memory card. Select campaign mode, then choose
"Load Game". Enter "P8H!H!P8P?H!?" as password to get all levels.

Level passwords:

Level 2
 4YH8H8PYP?H87
Level 3
 WYL8L8XQH?L8Z
Level 4
 !YP5P5?QH?P8Z
Level 5
 CZT5T5HRF?T8Z
Level 6
 KZX5V5PRF?X8Z
Level 7
 SZ75Z5XRF?78Z
Level 8
 6Z?595?RF??8Z
Level 9
 C6DVBVHSF9D9J
Level 10
 K6GVFRPSF9G9J
Level 11
 S6KVJRXCF9K9J