Nice song!
Even though a bit long, the intro hooked my attention :)
The instrument that starts at ~0:30 and ~2:10 seems a liiiitle bit loud and seems to cover the rest. I also noticed the drums were covered a bit too much; I'd suggest you make them a bit louder :)
The only real problem I see in that song is that it would need some variation in the intensity, or something like that. Don't misunderstand me, I'm not asking for a dubstep drop or anything, I just feel it would make the song better if it had some more evolution/build-up and variation. The drop doesn't sound "drop-ish" enough; try adding at least some "boom"-like transition effect. You can also add some more background instruments to make it feel more intense and filled :) There's also the end of the song that feels a bit sudden, there should be some outro (even just a fade out would help) ;)
For the rest, the instument choice and the melody creates an awesome atmoshpere. There's just the mastering that would need some more work ;)
Overall, it's a good song. There is some place for improvement, but it sound really good :)