At the title screen, hold B while selecting the arcade mode option to unlock options for "Vs.", "Single Play", "Couple", and "Double".
Select arcade mode, then highlight "Hard" at the difficulty selection screen. Press Right(3), select the "Hard" option, and begin a game.
Select arcade mode, then choose any difficulty setting. Press the Analog-stick in any direction, then press Up, Down, Up, Down, Up, Down, Up, Down.
Select arcade mode, then choose any difficulty setting. Press the Analog-stick in any direction, then press Left, Right, Left, Right, Left, Right, Left, Right.
Select arcade mode, then choose any difficulty setting. Press the Analog-stick in any direction, then press Left, Down, Right, Down, Left, Down, Right, Down, Up.
Select arcade mode, then press the Analog-stick in any direction at the difficulty selection screen.