Some really cool ideas in here, but it sounds really mechanical. To add some expression, try a few of the following.
-Change velocities from note to note. No piano player makes everything the exact same volume, even within a single measure. Crescendos and decrescendos make such a huge difference in communicating a musical idea.
-Tempo. Everything in here is perfectly in time like a robot. edit the tempo event and draw in some changes to make the music breath. Slow down a little bit at the end of phrases. At parts like 2:01, start fast and slow down toward the end of the run to be really dramatic. Oh my gosh, it would sound so awesome to do that...
-Simulate the sustain pedal. Pianists hold down a foot pedal that makes notes ring out, creating some really lush, beautiful harmonies. One way to simulate this in a sequencer is to drag each note value out so that they keep sounding after being initially played. Make the notes hold out until the chord is done (probably one whole measure for most of this piece) so that it sounds nice but does not become too muddy. Pedal alone will take this from being okay to great.
-Using velocities, bring out the important parts and lower the volume of the less important parts. For instance, the trill at :46 could come down a little bit because it is a decorative ornament, and the left hand could come up. In other spots, the melody could come up and the left hand arpeggios could come down in volume. This will create clarity and a sense of texture in the music.
What I do like is how effectively you utilize different registers of the piano. You use the entire range of the piano to evoke different tone colors. I also like some of the transitions and runs.
Take the time to make it sound more human and it will sound ten times better. Keep trying your hand at piano pieces! :D
(I still voted 5/5 on this, because the arranging is pretty good. I just wanted to give you some helpful tips that have been good to me in the past)
Shanath 
