Good idea, crippling design flaw and control bugs.
It was not a good idea to make the walkthrough a pop-up every couple of deaths. Don't ever do the walkthrough pop-up again. Seriously. At best, trigger it ONCE, to let them know there is a walkthrough, then put a button somewhere they can click to access. Being forced to deal with that pop-up every couple of deaths was hellishly annoying.
An even bigger problem is some kind of control-sticking bug. Something was causing my controls to stick or not register - that is, I would let go of the right key and keep running right, often straight to my death, many, many times. Then I'd get that pop-up, tap down, and promptly run straight to my death again, until I tapped the right key. Same for left key. And other times, I'd jump, hit the left or right keys, and stand perfectly still. And promptly fall to my death through the block I used to be standing on. Then I'd spawn and start running straight right again, or some other weird crap, until I finally couldn't take it anymore and had to stop playing.
It's a good idea, but the walkthrough thing was annoying and I can't control the little guy 'cause of the bugs. Which is a shame, because I want to play your game, but it's more of a chore than a challenge, as is.