Very nice song! I'm not speaking as one who has piano recording down to a tee, because piano is something I struggle with...having said that, if you want to take it up a notch or two I would try and give the piano some more space and panning if possible. The piano is coming across as mono on my end.
 
Possibly two piano tracks panned with bass keys on one side and higher keys on the other side. Not sure if you used midi or how you did the track, but if you could do that I think it would add more dimension to the track.