Unique use of the theme! You should make dark squares appear less the higher you go.

As Knox say , I think it lack a score system , with maybe a saved best score , graphics are pretty limited , but I like how the "mountains" doesn't repeat , is it randomly generated ? Maybe a little sprite for the character instead of a dot would have been nice , especially because the dot is not very visible when on a white pixel. But I like the concept ,it definitely have potential.

I managed to get 21,415 points! Took me a few tries to figure out how the game worked, but after that it was pretty easy I think. You managed to make good use of the theme in your game which is very nice. It would be nice if there was an ending though, that way you could try to get/beat your high score.

Yep I am one of those who could not understand what to do but then it gets better. I really feel this mechanic would make a good casual mobile game with some obstacles and different levels.

It was a bit difficult to grasp at first, but then was pretty simple.

Nice mechanic. It's just one step behind to be addictive.

I think adding a score on the top left/right would be a good idea!

Not bad; with some more polish, this could be a pretty decent game.
I imagine it'd work especially well as a mobile game (using touch instead of the space button).
Also, with some items to collect along the way, it could be quite addictive.