This is a fun book from cover to cover. My wife bought if for me for Christmas and it brought me a lot of twisted cheer.
The style and the way of thinking is Carl Hiassen meets Tom Sharpe with a dash of Sam Raimi thrown in.
Christopher Moore manages to pull off writing a book in which we care what happens to the characters, laugh at fights with flesh-eating zombies, cheer when Santa gets what's coming to him, root for the psychotic warrior princess who is off her meds and believe in a talking fruit-bat.
The only "reality" based thing in the book is the love the people feel for each other and their irrepressible response to all the craziness around them.
That, combined with great comic timing, an imagination that refuses to accept any limits, and a love of genre fiction, is what makes this book a joy to read.