Zack, Cathy, Charlotte, and their parents are going to Planet Gluco (which I can only guess was inspired by the word 'glucose'), and Zack requests to have his Nebulon best friend Drake join them. Gluco is a planet that would make Willy Wonka jealous. Once there, they have several contests in which Zack and Drake partner up for almost all of them. In a coincidence, Seth, the alien boy who originally bullied Zack, is there with his friend Howie, and they partner up for the contests. Cathy and Charlotte find some colorful painting activities to do. Their parents, I can only assume, are there mostly as chaperones. There is a moral in this about cheating in a game, but... that's... about it. This one isn't boring, but rather bland.
Honestly, this particular book would probably be more enjoyable to experience in real time. In story format, it comes across like someone's recollections of their vacation. Going on the vacation is always much more enjoyable than hearing about one. Not that I'm uninterested when someone tells me about their vacation.
I don't know. The repetitiveness of the planet hop mixed with this basically being a one-day vacation kind of doesn't go very far. This isn't fire-starting material. It's okay. 2 stars.