My idea is that maybe the antagonist of the game shatters the Melody Mirror which unlike the the dimensional mirror from Kirby and the Amazing Mirror, it doesn't lead to a mirror world, but a musical themed peaceful world that was corrupted by the antagonist, so he could steal the power of the world. Then the antagonist shattered the mirror so nobody could get in, and left bosses (I only have ideas for three bosses) to guard how many shards you want there to be. This is just an idea, I don't really know how this could tie into the other concepts, so you don't have to use this
If you like the idea I hope you redesign the mirror because my vector skills suck lol
