Like the game, the whole rewind mechanic is cool, but there is not a need for it in the game, I also don't really like how to rewind all your movements without anyway to stop it, for instance if I could stop the rewind by pressing lctrl again it could be used to save myself from a missed jump and also maybe require it at some points to that mechanic that you spent time designing required to be used. 

Another thing is the level design, while the fact that I can choose levels from the menu is fine, I would have liked a level progression where I start at one and go through all 6 levels, and if I die at a level instead of just booting me to the menu, I get re-spawned at the start of the level and can try again, instead of having to click through menu screens. 

One last thing, the menu sound track is really cool I love it, why not put it in the levels? 

I like your game though, the platforming feels really smooth 

It's good. Only thing is some jumps seem almost impossible (although there may be some sort of strategy to it I'm missing).