Cool game! I really liked how you introduced the mechanics progressively, the learning/difficulty curve is great!
As others have said, the controls are wonky though, since, when you try to jump, the game has to wait to see if you're wanting to do a short press, a hold, or a double press.
I saw on another comment that you noticed this problem halfway through the jam, and hesitated to start over, but I'm glad you didn't because I think you still made some cool dexterity puzzles to go along with the one-button mechanics!
Oh! And I like how your jump doesn't get interrupted by the corner of platforms! The game lets you slide up to put you on top instead! I wonder if you took the idea from Mark's last video about Celeste, but anyway it's great that you took the time to implement it!
I imagine the game would have been quite a lot more frustrating if you didn't, since, after a failed jump on one of those steps, you would have to double tap to turn around, long hold to move away from the step in order to reach it at your jump's peak, double tap again to turn towards the platform, and then tap to jump.
It would have been a chore.
Anyway, thanks for making the game!