The art is nice, but the music is great ;-). The game is a bit short, but probably the right length. The reveal at the end, explaining why the character can't go backwards, was great. Perhaps you can explore that a bit further in the game.
[spoilers] The part were you need to start moving backwards wasn't very clear to me. I kept on walking to the right and then got reset without any feedback as to what I was doing wrong. Also, were the puzzle pieces physical pieces? (that would make sense from the reason as to why you can't go backwards) Maybe you could have made that more clear.