The Legendary Starfy [NDS]
Beat the game (World 8) to unlock the Sound Test, Gachapon, and Boss Mode. Press R on the Stage Select screen to play them.
The following worlds can be unlocked by performing the actions below:
* World 9 - Beat the Game
* World 10 - Complete Big Bossdown (Boss Mode) with either character in under nine minutes
Unlockable: Alternate Ending
Beat the game a second time for an alternate ending.