I have a few suggestions/comments:
Though I am a huge fan of the works of Koji Kondo/other Nintendo composers, you--the arranger--can do some things to really improve this piece.
1) Dynamics really help express the overall feeling of the piece. However, this piece just remains at a mezzo forte the entire time. I would revisit areas in the piece where you could improve the dynamic contrast.
2) You could also improve the overall sound of the piano by adding reverb to make it less dry. It's kind of choppy and in there is no use of the pedal on the piano where it would be desired.
3) Since you are arranging from the original orchestral tracks, it is impossible for ONE piano to play all of the voices within the music. In the orchestral version, the composer would ideally have 16 violins, 12 violas, ect playing certain voices. I would recommend going back and improving the instrumentation. If you want this concerto to be on piano, then take out some of the unneeded voices or fix them so that it is *possible* to play on the piano. This will also improve the clipping, and the static that you would get during the big climaxes.
4) The transitions also need improving. Though you transition in interesting places, the bridges are so surprising that it actually takes away from the piece. Add a lead into each transition or slow down and hint that a transition is coming. I believe that this will also improve the musical quality of the piece.
I hope I helped! :)