I'm giving this a 4 star rating because it was a young adult book and it was cute and so I am overlooking some of the annoying pieces.
The main character in this book is a soul that leaps from body to body. Every night at midnight (made me wonder what would happen if he kept traveling away from the sun and was never anywhere at midnight?), he is forced out of his current bodily residence and sent to another. It immediately reminded me of Quantum Leap (old 80s TV show), but instead of having a job to do, A is simply stuck there until midnight the next night. The vehicle gives Levithan a great opportunity to show his ability to be empathetic to anyone (except the extremely obese) and showcase lots of characters, but doesn't provide for much of a plot.
I found the first third of the book to be quite good. I liked A's obsession with Rhiannon and his wish for a romantic relationship, but then I thought the book sort of fell apart. I didn't think he should have confessed to her (nor should she believe him) and I didn't like the added drama of the bad guy Reverand Poole. It just felt like Levithan was scrambling for a plot. Ultimately I think this had potential as a short-story character piece which would have left me wondering about so many things. Instead it just sort of rambled with no real purpose.
Levithan does a good job, though, with the psychological aspect of his characters. He makes some poignant and witty commentary about human nature: "After a while, you have to be at peace with the fact that you simply are." and "Kindness connects to who you are, while niceness connects to how you want to be seen." and "I am always happiest when I am just attractive enough. Meaning: other people won't find me unattractive. Meaning: I make a positive impression. Meaning: my life is not defined by my attractiveness, because that brings its own perils as well as its own rewards."
Overall it was slightly sloppy, but entertaining and had a cute premise.