I use this book with children of all ages and levels of development, as it appeals to almost everyone. I remember using it with a group of young children for the first time, and by the end of the story, several of the moms were tearing up. The illustrations in the book are great, and this is such a wonderful way to address emotions with children.
I have an older group of kids with whom I use this book, and they love to imitate each action in the book as I sing about it (especially YELLING!). It is definitely a resource that I will never retire.