Well, I liked this one better than the first one, however there were a couple of things I didn't.
First, for being a kids book, there was a decent amount of indecent language: Zack's dad: "Damn these antiquated machines" and lots of use of the word hell - hell-bent, snowball's chance in hell, and I believe just using the word once, but I can't really remember other than I know there was another instance besides the other two examples. Now, I don't normally care about this stuff, and I'm trying to keep in context that Andy Griffith's lives in Australia and Australians might not be as annoyingly obnoxious about "bad language" as adults are in America. However, Zack's Gran was a stickler for appropriate language, so it surprises me there is more than one occasion of "foul language" in a book that is meant for kids.
Second, and also in regards to the language business... the Uranus joke was just so overused in this book. It wasn't funny the first time, it wasn't funny the 150th time. Every time someone mentioned the planet, like "I can see Uranus from here!" Zack's Gran would go "Language!" and they'd say "I meant the planet!" Every. Single. Time. I wish I would have kept a tally because it was so obnoxiously overused I seriously think it'd be near the hundreds... thanks E.L James! Ugh -_-
Third, the ending seemed really rather rushed and ridiculous. I know... that sounds kind of silly right? A ridiculous ending for a book called Zombie Butts from Uranus? But Teresa, surely the entire book is silly? Well yes... of course the entire book is ridiculously silly, but at least some laws of science are present and accounted for. The ending, however, was just overly unrealistic and in the context within a crazy, unrealistic book itself, well it still seemed to be so unrealistic it was unbelievable in a book all about unrealistic nonsense. So therein lies the issue... if the ending seems far too unrealistic in a book all about nonsensical and unrealistic storytelling, that's probably a problem.
Other than that, the storyline was a little more interesting than the first. I liked it better. Zack's butt is probably my favorite character...other than his Gran!