We start with some pulsating droning with some sound effects. I'm really into sound effects, but on a musical level, I'm not so sure. This carries on for 2m 20s approximately.
Finally music begins playing! This bit is cool. You have a sort of ostinato going on that is finally met with some harmony from what sounds like an organ. You increase the harshness of this instrument, and it sounds really cool.
You break the ostinato and finally enter some sort of strange new ostinato, which I'm really digging. The atmospheric harmony plays perfectly with this.
Now from 3:55 - 5:28, you leave us with nothing.
So my rating for 2:20 - 3:55 is 3.5/5, because it was really, really cool. But the whole bit before and after that is just ambiance. Cool stuff, man. I look forward to hearing some more.