Is it engaging and conversational in tone? Do they appear in other books? Is the setting unclear and fuzzy, or can you easily make the movie in your mind? A child who doesn't like to read story books may prefer to read comics, magazines, newspapers etc. What makes it special or worthwhile?
Other formats could include a newspaper report or an imagined interview with a character. This isn't the plot, but rather the ideas behind the story. Why would you recommend this book to other children?