The following is from my review of North! Or Be Eaten posted on my personal blog:

This second book is a treat, even better than the first, but I highly recommend reading them in order. You'll better understand why and from what the Igibys are running, and you'll further be prepared to expect the random bits of humor in the story, the personalities of the main characters, and the footnotes on various pages in the book. Speaking of humor... this book is spot on! I love Andrew's wit and feel he's really improved since the last book at incorporating it more neatly into the story. I laughed out loud several times, especially when I read about Podo Helmer "quivering in a boat like a belcher's belly" and Janner Igiby being disturbed by the superfluous punctuation of the "FORK! FACTORY!" as he was about to be imprisoned in it.

In addition to imagination and humor, Andrew has filled North! Or Be Eaten with plenty of action. The plot is basically a series of clever escapes from trouble punctuated by short periods of recuperation and reflection. The character development kept me turning the pages just as much as the action. Janner's continued maturity is front and center as he grows into being a proper Throne Warden. On the other hand, Tink's spur of the moment immaturity brings a lot of heartache to the story as he rebels against his future as the High King of Anniera and gets himself in a boatload of trouble.

Speaking of boats and trouble... we learn a lot more about the mysterious past of Podo Helmer. He's just as tough, funny, and tender as always, but we also see his fears from his past catching up to him as the Igibys get closer and closer to the Dark Sea of Darkness in their flight from trouble.

Like all good fantasy children's literature, the Wingfeather Saga provides weaves sound moral instruction and personal character development into the stories (see the Chronicles of Narnia and the Chronicles of Prydain for other good examples). The characters are seen to grow in a number of virtues, including faith (i.e. trusting "the Maker" in a religion similar to Christianity), responsibility, love, forgiveness, courage, intelligence, and much more. We get to see them fail, as well, and learn how they get back up to make wrongs right. I can't wait to read these books to my children and help them wrestle through the very same problems and growing pains.