Playing multiplayer in the Gamecube Crystal Chronicles game requires using Gameboy Advances or Game Boy Advance SPs with link cables, but the Game Boy Advance SPs I have are old and their power drains quickly and they can't be plugged in to a power supply while playing the game because the cable blocks the spot where the recharger would be plugged in. Some of the buttons also don't work very well.
Gamecube controllers can be used to play multiplayer for most of the game. You will still need Game Boy Advances for each player. To do this, you must use the Game Boy Advances until you enter a level. Once all players have selected to start the level, the Game Boy Advances can be swapped out for Gamecube controllers and the game will play normally. Note that you won't be able to access your inventory or look at the maps normally displayed on the Game Boy screen. Also note that you will need to use the Game Boys to read the letters at the end and to select a new level.
If you try switching to the Gamecube controllers before selecting a level, it will just drop that player from the game.
Source: I've done this before.