Type L0SR at the password screen. You get a strange code. Start a new game or load a previous saved game.
Level 02: FWQPLevel 03: PLRQLevel 04: SZNFLevel 05: TD5SLevel 06: J1BTLevel 07: K2CVLevel 08: N3DWLevel 09: M4FXLevel 10: X5GZLevel 11: C6HOLevel 12: D7J1Level 13: F8K2Level 14: FGL3Level 15: JFM4
While playing press A + B + C.
While playing press A + B + C
While playing press X + Y + Z.