Take a spunky heroine competently surviving on her own on a deserted island (the ultimate kid fantasy). Add in animal friends who seem to understand, the vaguest of villains hovering in the background and easily overcome, a smattering of scientific information effortlessly absorbed, and a very satisfying conclusion. Then write it in breezy style, making the various pieces of the story fit together in a nicely coincidental, jigsaw-puzzle way. All together it makes for one delightful story.
As with other island survival tales, kids will want to be Nim, and her story will stimulate readers' fantasy lives. Unlike most of those other stories, it adds in touches of fantasy and humor to keep the gritty and sometimes scary reality of survival at a distance. In that way it's more similar to the non-island survival story, My Side of the Mountain by Jean Craighead George. Most of the fantasy comes from the animals which, while still real animals, are usually intelligent and helpful, and are anthropomorphized just enough to turn them into characters. This understated, easy-to-read tale, written with a light and loving touch, is a near-perfect middle-grade novel.