This is an enjoyable platformer. The assets fit together really well, and you're choice of boss music is something I can only agree with =D.
I don't know if there is a bug somewhere but when the boss music started I didn't see the boss anywhere (and I then well off the edge trying to find it). Some sort of checkpoint system could be a good idea as I died a few times close to the end and it would be nice to not have to restart the whole level. Overall it's a good game!