Ok.. That was pretty sweet. Although the mechanic isn't exactly new it was (IMHO) well executed. After taking several breaks I did eventually win the game. I do have a few suggestions though..
1. The key layout.. do not have us use the spacebar, the arrow keys, and the mouse.. I don't know why that seems good to some people, but I assure you it isn't.. Ultimately my way around this was temporarily binding my z key to right click. Make up jump or ditch the mouse... or both..
2. It is really not obvious that the torch is a torch when you first encounter it (level 13). Maybe have an NPC talk about what it does?
3. Level 20 (no time limit) can become unwinnable by the torches touching boxes (and thus not hitting the boss) because this level doesn't have a time limit it would be nice to have something respawn so you don't just have to suicide.. the same could be said of other levels where you accidentally create an unwinnable situation. That being said on timed levels you don't have much time for rectification, but the boss level is a different story.
4. As another reviewer mentioned the hitboxes for being crushed kind of seem all over the place, crushing you when you really aren't under it. You state plainly in the description that it is buggy, but it's Newgrounds we feedback.
Overall though really fun, I would definitely play a longer version of it. It does seem to be a great deal of trial and error and grinding... but that isn't always a bad thing. I'm sure this isn't your first game, but it is your first posting under this company. Look forward to seeing what else you can do.