Good for a first...
That voice (instrument) you used in the beginning got on my nerves rather quickly, and the tempo was very haphazard. A very nice melody, but the tempo was very hard to follow and made the song difficult to listen to. The volumn of your insturments should be tweaked a bit, and you need to use the parametric EQ to take all those squealing high pitched voices out. I think that voice would actually have been much better if you simply dropped it down an octave. Same goes for many other sections of the song.
Above all, put some variety in there. It was very, very repetative. But i can recognize a good composer, and you are one. Keep at it!