Bust-A-Move Millennium

Debug Flags
A hidden option that allows the player to change some variables can be accessed with GameShark code or Game Genie code  with a US or European cart. Go to the options menu, keep pressing down until going past Exit, then press Start or A. Press Start or A to change a value from 0 to 1. Pressing B goes back to the options menu.

The first row of variables selects which of the unlockable characters are playable, but it's unknown what the other two rows do.