Highlight the "Erase Game" option on the game selection screen. Press Down, A, R, B, Y, Down, A, Y. Press Select to change the current song.
Bonus games practice
Press Down, Y, Down(2), Y before the game selection screen appears.
With one life remaining, enter a level that was previously completed and lose your life. Press any button at the game over screen to return to the Cranky Kong opening screen. Enable the "Bonus games practice" code and play the bonus games to earn a surplus of lives. Then, press Start to pause game play, and press Select to return to the place where the last life was lost.
Highlight the "Erase Game" option on the game selection screen. Press B, A, Right(2), A, L.
Interactive two-player game
Highlight the "Erase Game" option on the game selection screen. Press B, A, Down, B, Up, Down(2), Y, A and start a two-player game. The inactive player can press Select at any time to assume control.
Hint: Mine Cart level
Jump over the edge on the right and hold Left until you hear a bang. Jump over one enemy to complete the level.