I haven't read the books. My daughter Perry (14), who's been a fan of the books for awhile very kindly invited her old mum to come along with her & her mates to see it at the movies. I enjoyed it but I cried quite a bit. Even though it wasn't gratuitous it's a very disturbing concept. Child soldiers are a hot topic at the moment & rightly so. Perry talked to me more about the book, about the politics, there being 2 sides to the story, different things like that which I was mightily impressed with because it shows that she really thought about what it was she was reading.
Like other people I did think of the Stephen king story The Long Walk. A-mazing story if you've never read.