This book has a lot going for it, but I wouldn't recommend it for every child.
A very positive point for this book, is that it's written at about a second-grade level. Equivalent to the "Step 2" or "Level 2" books. It's actually got quite a story, but it's written easily enough for beginning readers to enjoy, which is really great and sometimes hard to find.
I thought the illustrations were wonderful and whimsical.
The story itself might be a little tough for an already extremely empathetic child to read. Since it depicts the feelings of ducks who are being hunted, this might be a sensitive issue for some. Introduce this book to the child of a hunting family, or even just a family of typical meat-eaters and you might find yourself with an angry little vegetarian on your hands! (Especially interesting, when contrasted against Dahl's "Danny, The Champion of the World" - a hunter's hero!)
My children enjoyed this story (and still eat their burgers), but I think for some children, it might raise some ethical problems. Which isn't always a bad thing, of course! But parents beware! This story might lead to a domestic revolt.
Of course, any family of vegetarians won't have a problem with this story at all. And, as another reviewer mentioned, this book can certainly offer some good "empathy" discussions with children.