Sonic's Secrets: Chuck Rock 2 - Son of Chuck.
Level Skip.

To activate this cheat, pause the game (press Start) then press:

B, A, Right, A, C, Up, Down, A.

The game should unpause.

To skip a level, pause the game again and enter one of the following codes:

Press A + Right  to Skip ahead one level
Press A + Left  to Skip backwards one level
Press A + Up  to Skip ahead one zone
Press A + Down  to Skip backwards one zone