Great melody..
I like the chords you used, they are great. I just find one part a bit repetitive.
The pads are great too, they sound nice and airy..
You've added every subtle effect, which really enhances the song by alot.\
This would make a great trance song beginning, if you added a nice beat to it..
Maybe you should raise the volume of the piano at the beginning, it was drowned out by the strings.
Also, I can hear a limiter on the song. It kind of spoils the song as everytime the kick drum sounds, the rest of the song seems to duck away.. You should try to limit the kick drum itself, or use less heavy pads. They seem to be competing with each other for volume.
Overall, great song. The mixing and mastering aren't perfect, but the song itself is great.
Oh, and I think this would fit the ambient genre better. =)