The main issue with the mix I noticed was with the music box. I would recommend a low cut eq on the low end to about 200hz or so to get rid of unnecessary low frequencies, and some surgical cuts in between 1000hz and 2000hz to get rid of resonant frequencies created by the music box (make sure they are small because if they are large cuts they will get rid of the tone of the music box). Though looking back I think it's more of an issue with the youtube version, when I looked at the file you included I don't think it was as bad. Here's screenshot of the changes I made since that's probably more easy to understand than words. Hope this helps!