It's probably only a two-star book, but the aww-shucks hero made the whole thing too light and fluffy to really hate the fact it's mostly icky things that are old hat to the Internet strung together in a half-formed, Swiss-cheesed plot. It made a couple of good points, had a handful of amusing scenes, and tried too hard while not really trying hard at all.
KaBOOM is a great organization, and the philosophy behind it is common-sense and liberating. While Hammond comes off a little pushy on occasion, you can't fault him for doing a lot of good, and for laying out a mindset that encourages children not just to be children, but fully functional human beings.