If these levels are meant to be the transition between worlds, seeing as it goes from Toad Story to Fiesta de Los Muertos, then why the hell are the bosses still alive? Do you go to the next world and then come back to fight the boss? That sounds a bit backwards no?
Soar your way from one gorgeous realm to another and hone your dragon flying skills.
Mind the teensies clinging onto your back, though!