Thank you! I'm glad the level design came across well because I was trying really hard to teach the mechanics/entities in the game in the first ~10 levels and then do interesting stuff with it for the rest. I'd love to have had another 5-10 levels but I just ran out of time to create more content.
I did not write the song but I agree, it's great... the credit goes to David Harris - https://david-harris.itch.io/ost-many-stars