To unlock Mother Mosquito, go to the character select screen. Press and hold L1, then press UP, RIGHT, LEFT, DOWN, SQUARE, SQUARE, R1, R1, R1.

To unlock the Father Mosquito, go to the Character Select screen, then press and hold L2. Then press UP, RIGHT, LEFT, DOWN, SQUARE, SQUARE, R2, R2, R2.

To unlock the second year, fill all 16 Ex Tanks.

To unlock the Special Mosquito suit, earn the new mosquito colors on every stage.

To unlock the Reckless Cyclist mini-game, go to the main title screen. Rotate the right analog stick 30 times to immediately play the Reckless Cyclist game.

When you enter the Kitchen level (stage 5), go to the microwave which is on the table. When you enter it, a timer comes up. Collect all 8 heart rings and the heart in under the time limit (25 seconds) and get out of the microwave to gain 100 heart rings. If you fail, you die.