Better than most entries i've played. 

Only feedback i would give is that you don't revert the level after the player has completed it, even if they die in the second afterwards.

Secondly it's annoying having to hold down shift the entire time, i recommend making the shift jump just the default jump or changing the jump height depending on how long the player has held the space bar, like it is in most platformers.

I suck at platformers, but I really like this game in concept. Using yourself as a resource to complete puzzles is an aspect of puzzle games that I feel is underused and underappreciated. Keep up the good work and congrats on your first game on the platform!