Amazing game !
I mean, really, the graphism are awesome, the soundtrack is really good, the concept is nice too and it's fun to play !
There's just some really minor problems like the mix, the music could be louder and the soundfx (especially the coin) lower. also, I saw that you added a sort of symbol so we know where the spikes are, it's a personal taste, but I think it could be more visible, it's too merge with the wall texture.
But as I said, it's really minor and the game is really good, you did a good job !