Ditto to the above on the composition - really nice. I likes.
Mix-wise, I'd like to hear just a bit more space around the piano as well. Not a lot, I think the close-mic aspect works, but just a little presence. The other thing that I might try is lowering the velocity of the loudest notes just a smidge since they seem to be a lot brighter than the rest. I think that by doing that you could better gauge how adjusting the hi end affects the overall sound without those few notes getting too bright.
Again... nice.