I picked up The Roar at an end-of-the-year book fair after having it on my "to read" list for a year and a half. The buzz about The Roar is that it's exciting, fast-paced, and will appeal to fans of dystopian action adventure (i.e. The Hunger Games). The buzz is accurate, in my opinion, and I'm eager to see where Clayton takes this concept in the sequel.
The Roar is set in a future in which people are crowded (extremely) behind "the wall", a giant concrete structure. Millions of people are hiding behind this wall because of The Animal Plague, a rabies-like disease which struck all of the world's animals and forced the government to basically raze the entire planet with poisons. Meat is now grown in tanks and most of the food is "fab", meaning it is fabricated out of mold instead of actually grown. London now consists of two levels, one of which is worse than the worst 19th century tenement and the other literally a golden city in the sky. The children of the poor refugees who live in the lower level of London begin playing what they think is a video game, but Clayton gradually reveals that it is much more.
The strength of this book is definitely the interesting premise and the suspense created by the gradual revelation of a "secret" being kept by the government. Character development tends to be one-sided. Good characters are just good, and bad are just bad. The reader is rarely asked to make any kind of decision about which characters to like and not like as the lines are so clearly drawn between bad and good. Likewise, the interpersonal relationships portrayed in the book are mostly flat. Good relationships seem to have no flaws; even when a friend is upset at losing the game, the dissonance created by that upset is explained away and wrapped up nicely by a "sick mother excuse". I didn't find myself really caring about the two main characters, twins named Ellie and Mika, though I was interested to see what happened to them because of my interest in the plot. I wouldn't be upset to see any character completely left out of the sequel, so long as the premise was the same and the plot continued.
This book would work well for middle or high schoolers, though older high schoolers may find it a bit juvenile because of the flat characters. The characters are primarily 12- and 13-year-olds so the book includes school, friends, bullies, parents, and identity crises. There are a couple of violent scenes, but nothing too drastic or graphic. The book would make an interesting read for a Science class as it deals with issues of environment, artificial intelligence, and genetic mutations.