I'll start it short: This is a terrible book.
The premise is excellent, as is the cover. The execution, however, is amateurish at best and laughable at worst. There were some 4 star moments, though - the journey, to be fair, proceeded as follows:
3 stars, 4 stars, 3, 4, 2, 2, 1...
The second half of this book is so unsatisfying, and the ending so trite and faux-didactic that I had trouble not throwing it across the room. As a massive sf/fantasy literary snob (China Mieville is my hero), I was actually insulted to have been conned into buying and reading this book.
The premise is classic steampunk/clockpunk - what if the solar system were a giant clockwork mechanism, and the planet was winding down and needed to be rewound? The book, however, is classic bait-and-switch. There is no steampunk here beyond the premise, and after the halfway point the book just becomes tiresome and tedious. The main character is uninteresting, his 'perils' uninspiring, and we are never concerned that he is in any danger of failure on his quest. Actions, scenes, characters and ideas are thrown around, but the author never does us the courtesy of explaining them. The message of the entire book seems to be 'trust in god' which never sits well with me anyway, but this message isn't even delivered in an interesting way. A massive, massive disappointment, and I should probably give the book away to someone I don't like.
Have I mentioned how terrible this book is? Well, let's ignore a pointless sex scene thrown in randomly later in the book to establish a growing bond between the main character and his nominal girlfriend; let's ignore the impossible nature of the equatorial gear crossing (Imagine the worst possible writing mistake about a world where the baseline earth is a giant clockwork mechanism and the concept of gears is fundamental??? Try thinking about the shape of a gear for a second, just one second, a fraction of time less than it would have taken the author to google a picture of a gear, for example...); let's ignore foolish exposition and grade school philosophy and metaphysics that makes the Matrix look like holy revelation by comparison; let's ignore long, tedious travelling scenes followed by condescendingly short and ridiculous action scenes with monsters who appear for no reason and out of nowhere... What's left to ignore?
There was a tiny fraction of potential in this novel, and it was wasted.
I think Jay Lake should go read
Polystom: Two Universes in One Reality (Gollancz). That was an excellent take on a similar idea. It even had a point! This, however wasn't and hadn't.