My dad once said to me, "You give a lot of books three stars." I do.
I think this was one of the first Animorph books I read, and it's not a bad introduction to the series since you get to see every character's point of view (Ax's first narration comes in this book). The story is clever, though it gets a little repetitive at times since we're occasionally shown the same event through different characters' eyes.
One thing I don't like is the cover. Why is Cassie shown morphing fly? She does use the morph in the book, but she does several others they could have picked from. Same for Marco, why is he shown morphing wolf when gorilla makes more sense? I don't think they were worried about repeats in the cover art because Rachel is shown morphing bear which was the cover of the book immediately preceding this one.
Spoilery discussion under the cut
Also Visser Three has a video feed on the Veleek for part of the book, but why don't they have a security system at least for the Yeerk pool? I mean, they've been attacked there twice now. Their Kandrona has been destroyed. It just seems strange to me that this alien race with advanced technology never thought to throw a few security cameras around their most secret bases. Maybe they do and I've just forgotten?