I thought it was going to be more planned out and useful. It uses the words "petty gods" in the wrong way. When used in the past, it referred to gods warring over petty rivalries at the expense of men. Thus, I thought I would find a lot of good antagonists and bosses, but found little in that regard. It's a book of humor to entertain yourself on a monday night, not a useful role-playing supplement.
The book includes the mostly useless demi-gods, servitors, cults, magic items, scrolls and spells.
There are things there of use, but several themes are repeated and many of those "petty" (or rather, "pitiful") gods and other individuals and items would be best served as a simple list of gods and other stuff with unstatted single paragraph descriptions, like a glossary. I'd be far more interested in one or more mythologies demonstrating the petty rivalries of lesser gods, common or previous unheard of, that earn them the name, rather than a loose assortment of demigods most of whom are absolutely meaningless to game play. I was hoping for some bosses, but barely 1 in 10 are worth any use. The listed magic items should be related to the gods shown, but most are just simple useless magic items that don't really belong in a book about gods.
As the Preface indicated, they were rather enamored with the name, just as I was, (It's a great name,) but had absolutely no plan in its execution. (A great name is meaningless if you are not inspired to a great plan.) Like the box, Reflecting on Unknown Gods, indicates, its not very exciting.