Oh, man. I REALLY like the sound work here. The pads at the beginning, deep and full, but with higher-pitched ones that really fit with the ambience. Those percussion effects (that cymbal-scraping - is it from a Jam Pack?). The drums, exotic enough to interest but subtle enough not to get in the way. The way that the low strings and organ just mesh. That bassy pluck that gradually fades in around 2:30. I'm enjoying this. :D
While your sound work is excellent, I think the composition here is a bit repetitive. Of course, ambient music typically is, but perhaps the bells that came in at 1:41 didn't have to go on for that long. Also, I felt that some of your synths had a bit too much resonance. Still, for the most part, I think you definitely hit many of the right spots in deciding when to introduce/take away instruments. Your melodies are also very well suited for making creepy and spooky atmospheres. :)
You're so lucky that you have a music tech class! Wish we had one. Anyways, loved your sounds and the mood. Great job! Don't overwork yourself!