Sinister indeed
First, I don't particularly like the intro. It's a little bland and it seems you use the same sound throughout the song. A softer intro is what I'd recomend given the overall theme of the song.
Starting at 1:24, it feels like you're trying to build up to something in the effect of a grand crescendo, but it simply drags on until you reach the last segment of the song and it ends.
However, you get a few points for letting the song loop effectively if it needs to.
These are just a few of my first impressions of the overall song. Hope I helped.