That is a lovely game you have there!
The comments below already pointed out the main points: Minimalist is good, gameplay smooth, great use of theme and music is work of art!
To try to give you something more:
-I feel like some clues for traps during the last flying level are appearing late on screen, making the time to react close to hard reflex games... I just found myself crying to my mom saying "I swear there was nothing here before" :'(
-Also someone said it already but the middle of each level is wandering around without info, sometimes with multiple ways to get to the same point, I see the purpose but it feels useless... Maybe add a little reward for taking the hard route would make it useful? (like strawberries in Celeste)
-It is while writing this comment that I understand the story, especially the triangles treachery when you fly first. I did not understood why the left me falling haha. Maybe make the blocks in white with red dots. It links to the next levels and make the whole world more logical imo.
Last but not least: How did you make that camera so smooth???? Please teach me!
Anyway, great job !