lovely
The melody is very nice. I like how it progresses. There's a fair amount of harmonics, with plenty of movement to keep me interested. Some good percussion, although in the more quieter parts of the song, I found the rim hits a tad distracting. Nice beat variation, and different drums for different sections, worked well.
Your sound effects near the middle certainly changed the mood of the song, although I found the contrast a bit too much. I would make them a little bit more suttle, or work on the transition a little bit.
The buildup was superb. It really brought life into the track. I can hear the effort and emotion you put into this track, it really shows.
For the record, I really don't know much of anything about ambient / IDM, I'm just typing my thoughts :)
Best of luck to you, man.