I thought the controls were a bit unintuitive, and that's what made a lot of the platforming difficult, since I was pushing some of the wrong buttons at the wrong time.
In addition to Hedgein's suggestions, I think keeping the player from being attached to the wall until they press themselves against it would help a lot. There were times I wanted to double jump straight up against the wall, but couldn't because I would have to do a wall jump, throwing me in an unintended direction.
Having the timer not start until the player moves was a great idea!