You know what this would be great for? A video game like FEZ. You know, where ambiance is everything?
So I have very few complaints about the song by itself. It's really good. I'm not too much into ambient myself but I enjoyed this.
Only little thing; in the first part of the song, even if it was to let the reverb ring, I think some sounds could've started earlier. Sometimes the pause between two sounds was a little long. Other than that, amazing ambiance feel. Great job on this one.