This is cute and fun, and a great basic intro to coding principles. It does seem like it's doing a lot of set up and then has kind of a cliffhanger ending just when it was maybe getting really interesting? But the characters are great, the art is fun, and it's a cool concept.
I was thinking about booktalking this to junior high but I think it really skews lower, 4th/5th/6th grade, although some interested junior high kids would probably enjoy it too.