Puyo Pop Fever cheats and cheat codes for Gamecube

In-game reset:
Hold A + B + X + Y and press Start during game play to return to the main menu.

Unlock Popoi as playable:
Finish the WakuWaku course in normal mode.

Unlock Carbuncle as playable:
Finish the HaraHara course with maximum 4 or minimum 12 fevers without
using a single continues
or
Finish the game once, but your number of continues will be 7 or multiple of 7.
(example: use 7, 14, 21 etc. continues to complete the game)