I think the presentation of this game is really good and I enjoyed the experience. Here's a small list of issues that I found while playing:
Buttons do not react to the player moving over them. (there is no way to know that a button is a button without it reacting to the player, except for appearance)
There's no way to track how far you've gone.
Also, I was able to break the game. When falling right after I pressed a button I got stuck on something and couldn't move at all: