Overall - impressive.
It's complex. Very much so - and I can only begin to imagine what the Piano Roll looks like for the channels. The individual melodies are clean, and pleasant, and I can hear that the track tells a story - whether this is intentional or not, I don't know.
However, there are a few things that I noticed while listening to this, chief among them is that all of the notes are playing at the same velocity, or at the very least, similar. This makes it sound like it is in fact a machine and not a real piano - and one of the things that FLStudio's keys generators have going for them is that they sound very real, especially with the inclusion of variable velocity on the individual key presses. If you were playing a piano in real life, you wouldn't press all the keys with the same force, and that allows you to simulate that...
Second - while the main melody is really rather pleasent, and the secondary melodies are as well, there is some dissonance between them, which, in some cases is ok, but not for this type of track. It makes it sound... off, like one part was not written for the other, and someone is blending them on the fly.
Finally (i know, I'm going on forever) there are parts of the track that, if played in real life, would require at least two people at the piano. This isn't bad, it just breaks down the sense of reality in listening to the track.
I hope that this criticsm doesn't come off the wrong way - the progression and the melody are both quite nice - it just needs some touching up =]
Quick not on dissonance: If you ever have an opportunity to do this it helps. A lot. Get together with a friend and have them sing a solid note. Doesn't matter wich one. Then, you, match it. If you are both sounding the same note, in your ears, it will sound like one solid note. Then raise (or lower) your note until you can feel an amost harmonious wave from one note to the other - that's harmony and both of these are resonance. Now raise (or lower) again, until you feel a warbling, or even, in some cases, a very unpleasent stuttering, not unlike having a window open to the "annoying threshold" n a car - where the air makes a repetitive thumping sound. That's dissonance, and that's what's happening with some of your "right-hand" notes on this piano track. Not severe, but still there.
Overall, though, not a bad piano track. and I hope my comments are helpful =)