Puyo Pop Fever
All characters and intermission sequences
At the options menu, choose the “Gallery” selection. Highlight the option to view the intermission sequences, then hold X and press Up, Down, Left, Right to unlock all characters and intermission sequences. If you entered the code correctly, you will hear a sound.
Hidden mini-game
Blow into the microphone at the title screen until a number appears at the bottom of the touch screen. Use the stylus or blow into the microphone to keep the falling Puyos from reaching the bottom.
Play as Carbuncle
Either get less than four or more than twelve fevers without any continues in HaraHara mode to unlock Carbuncle. Alternately, successfully complete the game with your number of continues as a multiple of 7.
Play as Popoi
Successfully complete WakuWaku mode to unlock Popoi.
Bonus gallery pictures
Have the Game Boy Advance game Puyo Pop Fever in the cartridge slot to unlock bonus pictures in the gallery.
Alternate title screen
Successfully complete WakuWaku mode in single player mode. Rider will now appear instead of Amitie at the title screen.
Control menu screen
Blow into the microphone at most game menus to move bubbles around.
Taunt
While playing the game, blow into the microphone.
The image featured at the top of this post is ©Square Enix.