It is said that Noah Barleywater runs away is a mere children's book. An adventure but not more than that.
It is also said that Noah Barleywater is a thought-provoking novel, even for adults.
What side am I on?
It's aimed on children aged 8-12, but I believe there is so much more in it that makes it a wonderful read even for adults. You can read this book on different level. It's not incomprehensible for an 8-year-old, but he/she will read this as an exciting adventure. Even as 'just' a children's book, I like the style. It's the kind of book I would have liked as a child. Now I'm older, I like that there is a bit more to it than just the story.
Note: I read a Dutch translation of this book