Two player mini-game
Hold Start + Select on controller two after turning on the system. Press Square to move forward, X to jump, and Triangle (when the power meter is full) to do a super attack. Alternately, hold L2 and continuously rotate the Right Analog-stick clockwise at the title screen.
Father Mosquito
Enable the "Mother Mosquito" code. Then, hold L2 and press Up, Right, Left, Down, Square(2), R2(3) at the character selection screen. A shout will confirm correct code entry.
Mother Mosquito
Hold L1 and press Up, Right, Left, Down, Square(2), R1(3) at the character selection screen. A shout will confirm correct code entry.
In-game reset
Hold L1 + L2 + R1 + R2 and press Start + Select during game play.
Unlock Cycle Minigame
At the title screen, press and hold L2, and then rotate the right analog stick 30 times. If done correctly, you'll hear a chime and automatically go to the cycle minigame.
Year 2
Fill each of the sixteen Ex Tanks to unlock Year 2.
Special costume
Unlock all alternate costume colors on every level.