Pause the game, then hold Ctrl and enter one of the following codes to activate the corresponding cheat:
Level select: Up, Down, Left, Right(3), Down, Left
Level skip: Right, Left, Up(3), Right, Left(2)
Infinite lives: Down(2), Up, Down, Right, Down, Up(2)
All extras and bonus levels: Right, Up(2), Down, Right, Down, Right
All characters: Left, Right, Left(3), Up, Left(2)
Temporary invincibility: Left(2), Up, Left, Down, Right(3)
Turn coins into Mad Garibs: Right, Left, Right, Left, Up(2), Left, Right