Just checked it out now, thanks for the feedback!
I've watched a few people play now, and it's clear to me that I've fallen into the age-old habit of assuming something is too easy because I—as the developer can complete it easily, resulting in me making overly convoluded and difficult to read platforming puzzles, such as the one you called it quits on.
You mentioned you felt you were fighting the controls throughout the session —I imagine mostly in regards to the high-jump mechanic and the unforgivng stamina? In any case, I imagine it'd make a lot more sense if I were to implement the high jump as a stationary "crouch jump", instead of forcing the player to have to dash with such little room on the platforms, and tripled or quadrupled the stamina while slightly reducing the recovery speed.