Hey there,
thank you so much for writing down such detailed feedback! It's always cool to read that people have an overall good experience with the game. I really appreciate it and it really helps to see where people get stuck or have problems to advance in the game. You make many good points about where things are not as clear to the player as I thought or where the player might expect more to explore (e.g. a few people told me they expected another puzzle at the very end instead of walking straight into the white).
Regarding the music I'm not sure what you mean by 3 different soundtracks? Actually each area already has its own music (except the last one, which is the track from the first "cutscene", but in another version). Some might be quite similar, but they are different tracks. I thought about releasing the music as well, but I'd need to find some time to do some editing, as they are now looping tracks. :)
Thanks again!
(and sorry for the laser ;) )