It's a fun and challenging game, I like it :)
Just a few things I noticed. I am not sure if it is on purpose but you cannot jump if you are on a slope. Which can happen pretty often and is often annoying if I click jump and nothing happens. It would also be nice to have a pick up sound for the coins, so you are actually feeling you are collecting something. Sometimes I don't even notice if I got the coin. And it is also possible to unpause the game while in the retry menu.
Other than that, a well done game. I also like the simple graphics.