I really like the core mechanic of understanding the music to move around. The enemies - snakes turning to grass etc. - is a nice touch. I like the idea of the worlds being so distinct.
Currently I found the timing a little too difficult, but not impossible. Moving to a new room felt satisfying.
It would be cool to see more interactions between the worlds - e.g. hitting a button in one to open a door in another.
Good game, I liked it.