I was not into this story in the beginning, but I cannot ever leave a story hanging no matter how uninterested I am, and I'm pretty happy I stayed on. The narration, as everyone else has stated, was so insanely perfect. Gravely, insidious, and yet still clear as a bell. My favorite bit was the description of the kid's skeleton popping out of his body while trying to run. Such a vivid image. Mrs. Bold's death scene was super graphic, almost distractingly so, but I didn't mind too much, since I was honestly rooting for that character to die. To me, she was simply a narcissistic, "good-ole" girl who put on a mask of purity for everyone else. I thought her dream scenes were strictly masturbatory; she was just so pleased with herself and the "good" she was doing to the neighborhood, she literally got off on it.
I actually was rooting for the monster to go free and take out all the people that had created it. Self righteous people who believed that the greater good was worth killing kids for deserve to have the same exit. They were the real criminals in the town, not these petty thieves and vandals. Not that I was wanting David to lose, just would've been cathartic to see the people who had made the beast in the first place get a taste of their own cruelty.
Also, anyone else reminded a little of the twist in Hot Fuzz?