All songs:
Select Arcade Mode. Select Play Mode, go to
Hard. Press Right, Right, Right.
Unlock Little Mode:
Select Arcade Mode. Select any difficulty.
Press Up, Down, Up, Down, Up, Down, Up, Down.
Unlock Mirror Mode:
Select Arcade Mode. Select any difficulty.
Press Left, Right, Left, Right, Left, Right, Left, Right.
Unlock Hidden Mode:
Select Arcade Mode. Select any difficulty.
Press Left, Down, Right, Down, Left, Down, Right, Down, Up.