This was a cool game! The rain looks great. I only figured out you are meant to ascend by falling first after layer 3 or so. The enemies that woosh at you teach you that really well, you just naturally see how it works as you dodge them. It was fun to ascend normally before that, gaining height bit by bit, dodging only when necessary.
A small nice thing to have would have been a particle-based indication for timing your dips and pullups, to have something to go by besides the sound.
Enjoyed reading the behind the scenes!