The Golden Compass is actually called Northern Lights in every place except North America. I guess the publishers thought that kids would get confused, because they would not know what lights could possibly be doing in the north. Never mind that the book never refers to the titular object as a compass; that’s not confusing at all, no.
It’s like how the first Harry Potter was renamed “Sorcerer’s Stone” from “Philosopher’s Stone” in the United States (but luckily not here). Because, publishers must think, kids are dumb; they wouldn’t want to read a book about philosophy! Never mind that the idea of a philosopher’s stone has been around for centuries. Just rename it and kids won’t have to learn anything new.
With that out of the way: While I’ve just referred to The Golden Compass as a kid’s book, it’s really not. Not any more than Lord of the Rings is a kid’s book. It may have talking animals and magic, but there is also disturbing violence and very adult themes. There are polar bears in this book that will chew your face right off.
It’s also no secret that Pullman is a raging atheist, but while it shows in the novel in subtle ways (incorporation of deep scientific principles, and participation of the Church in certain questionable activities), he never beats the reader over the head with it. It’s more atheistic by omission; there is no fuzzy feel-good God-is-watching-over-us and the-lion-is-Jesus message. Not that there aren’t feel-good moments, because Pullman creates characters that you’ll actually care about, who interact in very human (or human-like) and touching ways.
Overall, The Golden Compass is a dark, touching, epic fantasy novel that is just chock full of giant killer polar bears. I really enjoyed it, and look forward to the forthcoming movie (though it looks to have been pussified quite a bit, leaving out the disturbing parts. boo.), and to the other two books in the trilogy.