Thank you for the constructive feedback. Many have commented on the controls, but you are the first to comment on the fact that the game has to wait to see if you're wanting to do a tap, hold, or double press. "Waiting" is exactly the right word for it, and that's exactly how it's implemented in the game's code as well.
I'm also glad I didn't trash the idea. As I've said elsewhere, it was a nice exercise in level design under extreme restrictions. I have watched Mark's video about Celeste, but I wasn't considering it when designing this game. The way I was thinking of it was this: if you tapped the button and you were grounded when you started the tap, you intended to jump, so you should get to jump. The game shouldn't punish you for not jumping with that sort of precision, especially when there's a delay between pressing the button and actually jumping (due to the "waiting" I described above). I'm glad it's consistent with what he mentioned in the video, though.