If you dont know already some guys on youtube got the japanese version of brawl and hes been posting videos like crazy, he has some boss fight videos from the new adventure mode,"Subspace Emissary,"there are some pretty awesome bossfights from other popular nintendo games such as Ridley from Metroid, Pokey from Earthbound, and Rayquaza from Pokemon. And with more bosses to come they've added a new unlockable mode as of similar to All Star mode from melee they,ve come out with a All Star BOSS Mode just for brawl. It,s very cool just look up "ShadowHero" and a bunch of his videos should pop up, enjoy, if you have any questions about bosses just ask me or just look'em up yourself.
See ya!