Cute lil platformer, but I suck at platformers, so I also didn't make it too far. I found the platforms moved a little slow. I got game over a few times just waiting for the horizontal platform to move back into position. Personally, I'd remove the duck on the music when you collect coins, or at least greatly minimize it. With such quick sfx, the duck becomes painfully obvious. It'd be different with more elaborate sound design, but with something this minimal, I do not think ducking the music is necessary.