Great idea, but has a few flaws.

It's an interesting idea, but there are three things that I don't like about it.

1. The piano sounds like it is being played by the computer. You need to hide the "computerized" feel of it by making the notes a little longer or adding more reverb.

2. The song sounds somewhat empty. You should add a couple more instruments. Another idea would be to take two pianos, have one play the low notes and one play the high notes. Make the low piano sound rich and meaty (kind of like it does already), and have the high one sound barren and thin (achieved by correct reverb settings). The effect of this can be increased by having slight variations in the pan of the two pianos.

3. There are many areas in which the harmony is lost, and it just sounds like somebody is slamming as many fingers as they can fit on the piano.

Other than that, I really like the song. Especially the little sequence between 2:17 and 2:26. That was masterful. In fact, I would kind of like to see the midi for this, I might be able to work out a few of it's problems. Nice work!