Whirl Tour

Unlock every default stages:
Press B, B, B, L, Right, Down, Y, Up, Left, X, B, Down, Up, R, L, Down, Down
at the main menu.

Unlock bonus stages:
Press Up, Up, Down, Down, Left, Right, Left, Right, B, X, Y at the main menu.

Unlock every race stages:
Press B, Y, X, B, L, X, R, Y, L, X, R, B at the main menu.

Finish all objectives:
Pause game play in story mode, then press X, X, B, X, X, Y, X, X, L, R.

Unlock all stages and characters:
Enter Y, B, X, Y, Down, Right, Up, Left, L, L, Right, Right, Down, Up, R, X,
Left, B, B, Down at the main menu.