I see some people say that the mechanic is confusing at first... Honestly, I don't think so.
The three things I think that are worth mentioning as "bad things", are that the yellow area for completing the game only seems to be triggered when you are right in the middle, at first I was confused by that, the player being able to run would be a great add, in games, making the player faster is not enought, it's when you make the player able to run that they feel fast, and the level 5 is buggy for me, doesn't work at all
Great game