Everything is in the title. We’ve had musical note blocks since SMB3, Super Mario Galaxy has a musical world full of drums and stuff, and even Mario Kart 7 has a musical track where you powerslide on a piano. And of course, earlier Mario games and Super Mario Galaxy have been known for their incredible soundtracks.
That kind of world tends to become iconic because everyone loves music and instruments. The original Rayman game (the one people fondly remember despite being too difficult and not holding a candle to Mario, Sonic, Donkey Kong and Mega Man) had a musical world, and it was by far the most whimsical and memorable place in the whole game.
Musical world would rock.
I’m not sold on Music World. I keep having Wii Music flashbacks for one. But the world has no strong visual themes. What would the stages be other than warehouses for band equipment?
Rayman’s music world seems uninteresting.