We have cheats for this game on PlayStation, Nintendo64, and sometimes cheats from other systems may work on the Nintendo64 version.
Bust-A-Move '99 Cheats & Codes
At the title screen, press B, Left, Right, B. If you entered the code correctly,
a small green face will appear in the lower right corner of the screen. Then,
select puzzle mode and the "Arcade" option to access more puzzles.