I would recommend this for kids age 4/5 to 9. It is a really terrific book. The illustrations are really fun, and it was nice to see the whole treehouse in detail.
The characters were so-so. I didn’t really like Terry, he was a bit cocky. The way they acted (to each other and also towards others) reminded me of the Angry Beavers.
It was a fast read too. Didn’t expect that, considering the book was 200+ pages, but I got through the book in less then an hour.