Well orchestrated, nicely done! I really did enjoy this! A couple improvements I could suggest though:
-You need contrast in the volume. Your instruments are going at a very steady volume, and so the punch you composed isn't getting played! Time to fiddle with the levels!
-The piano, while lovely, is a bit repetitive. See if you can't get a bit more out of it by making the arpeggios have a couple 'filler' 16th notes. You're in a slow 6/8 or a fast 3/4 timing, so you can mix it up a little by having the 4th arpeggio played in double-time. It would give the piano just a little more complexity.
-Finally, keep putting stuff like this out! It was awesome!
-Ceevro