Okay, the rundown is as follows: This is a wonderful satire of two groups of disaffected people who somehow find their way in the world through karaoke and murdering each other. While this is well-written, it's more about the relationships between the two groups, whose dwindling members are experiencing life and bringing each other closer by slowly picking off the other side. The murders are a very small part of it. The characters are overly-cartoonish and sociopathic, but if you can get beyond that, then there's a rich, very twisted comedy hiding between these covers, and one I suggest people read.
On the other hand, the characters are all cartoonish sociopaths with no real moral compass, the novel doesn't give us anyone to root for on either side, and the whole thing seems a little too over-the-top for its own good. It's like a roadrunner cartoon disguised as social satire. When the devastating consequences of the actions taken in the book finally come to a head in the final chapters, it comes as something of a shock-- no one's really been chastised for their behavior before now, they've merely existed in a cartoon, and to suddenly have psychological and physical consequences reached at that point kind of seems needlessly cruel. Even for characters as unsympathetic as this.
But in the end, I enjoyed it. As nasty and twisted as it was, it's an interesting way of looking at the social issues in an urban environment, and a good satire of those "life-affirming" books where the heroes are brought closer together by some kind of event. Also, I didn't quite see the ending coming, and that's always a plus as far as I'm concerned. More as always, this time with spoilers, below.