FIts the environment.
Well, this song really has some tension, like you're in a basement or cave in a game with monsters and stuff. It would fit the environment it's meant for very well.
The beat has diversity, and I like that. It's not continually the same, but something that changes.
There's a few downers though, and that would be that it's drums and percussion ONLY, which can become a bit boring, especially because there's some kind of tension. Also, some of the instruments sound like they are played slowly, where you'd probably be better off using low-played instruments played normally there.
A 7 is just fine.