Bust-A-Move 2:

Arcade Edition

Bonus Characters (vs)

Do the "another world" code at the title screen (L, up, R, down) then instead of going to the puzzle mode, go to player vs. player. Once you get there you can choose your character. Depending on how far you have gotten in player vs. computer, more characters will be available. If you beat the whole game then you can choose everyone.

Level Skip

While playing a level, press Z, L, R, and A at the same time to skip to the next stage.

Hidden Characters (Puzzle Mode)

At the Puzzle Mode screen (were you select A or B) press Left, Left, Up, Down, L, R, L, R, and then L&R at the same time. This will bring up a character select screen, in which you can select either color dino, or one of the bosses. Be sure to press each button slowly -- don't go too fast.

Another World Code

On the Title screen, press the L Button, Up on the Control Pad, the R Button, then Down on the Control Pad. If done correctly, a little green dude will appear in the bottom-right corner of the Title screen. When you go to the Puzzle Mode, notice the Another World option below it. This new option is your ticket to a brand new world of puzzles!