I like the pixel art, and the music fits pretty well too. I feel like it gets way too fast, way to quick, and the jump curve could be a bit more forgiving, right now it's way too quick and steep. I think if you want to make it go this fast, it should get to this speed much later, and the speed should affect the movement of the background a lot less. That way the speed could increase, but it would be a lot less nausiating.