I must say, this has got some very interesting rhythmic oddities without there even being any percussion.
Towards the end, where the Song of Storms is played, AmIEvil makes a pretty ballsy decision to stick to the 4/4 ambient relaxation instead of going to the very obvious and forthright 3/4 waltz that the Song Of Storms really is. I mean, that song epitomizes "waltz". It's about as un-subtle of a 3/4 as you're going to get.
Bravo for pulling that off and sounding good doing it!