I like the game and the concept is fun. One improvement might be that when the player isn't moving on screen (against a wall or so) and one is holding A or D down the timer continues, even though the character isn't moving. I am not completely sure how the timer mechanic is implemented but if it isn't already like that maybe you could link the timer to the players velocity instead of the inputs as it seems it is currently done.
To me that is a minor detail and I overall really liked the game and was impressed at how much content there is.