I would describe this game as Nobilis meets Sid Meier's Civilization. Player portray the gods of a primal world whose actions and adventures shape human communities and could possibly steer the fate of the first human civilization. The book does a good job of driving home the mythic and epic scope and themes by using imaginative characters and setting information, awesome examples, and stunning artwork. If you're a fan of Nobilis, Scion, Exalted; if you've imagined playing the god of a world created by Robert E Howard, then I think you'll enjoy this game. Some of the ideas sparked in my mind were creating the pantheon's of Percy Jackson, or Marvel's Asgard using this game. I'm strongly inclined to create the original Changeling: the Dreaming kiths and the Justice League as gods using this system, too.
Speaking of the system: this game using Fate Accelerated and tweaks several of the dials and adds some new systems to better represent the themes of gods devolving into monsters. Chris Longhurst has renamed the Approaches to better suit the mythic genre of Gods and Monsters. The renamed Approaches are as follows: Bold (Flashy), Wise (Careful), Mighty (Forceful), Swift (Quick), Subtle (Sneaky) -- and Clever remains unchanged.
Cons: This brings me to the major downside of this book, the editing. At one point in development, I guess Clever was renamed to Cunning, and they changed their mind, but there is still a reference or two to the Cunning approach. There are also some typos. I say it's a major downside only because some people might expect these simple mistakes to be non-existent in such a professionally done product from Evil Hat. I can forgive these mistakes because I'm an Evil Hat fanboy. Your mileage may vary.
The alternate rules for the game about investing your god's power into stations and how to prevent yourself from devolving into a monster are a little complicated for a Fate Accelerated product. I'm still trying to understand the the concept of the god's mantel and how it works, but they provide several examples to help facilitate that. I only wish there was a more exhaustive example of play. I love the Fate Core book and each section gives an example of how that rule works in the game. I wish every book included that, but I understand the constraints of word- and page-count.
How do gods become monsters? Put simply, each of the approaches has a counterpart, an opposite. The opposite of Wise is Swift, the opposite if Clever is Mighty, the opposite of Bold is Subtle. Your god or goddess, based on its nature, has three Ascendant approaches; these are like "signature" approaches. Every time you spend a fate point for any reason (or, if you like, also use a free invoke for any reason), you move a token along a sliding scale toward the approach used in that action. This is acting with intention and it increases your power ... and when your power goes off the scale -- you become a Monster! Becoming a monster is like a form of concession... in which your power twists your nature and you become a monster with a corrupted, yet powerful, nature and the monster is in the hands of the GM. But, when you do this (if by choice for some reason), you get to dictate how the scene ends. Then you're off to make a new god PC to play with.
Another cool mechanic of that sliding scale of intention is that you will rename your aspects if your intention goes in the opposite direction. So, for example, you will see the 1966 Batman have an Ascendant Approach of Bold... and then over the years his actions moves his intention (and power) along the scale to it's opposite and his nature changes and his new Ascendant Approach becomes Subtle. He renames his Two-Fisted Justice (Bold) Aspect to The Dark Knight (Subtle).
The book comes with an adventure for you to GM with your friends (or family). Your god PCs have to fix the world after something swallows the sun! So, that will be really cool. And the culmination of your PCs adventures will be the parable told to human children by the communities to which your pantheon of gods is patron... "And that's why, when she feels like it, the Moon stands before the sun and brings night during the day..." stuff like that.
The bottom line: download it, give it a read, give it a play and when you like it, throw some dollar bills in Evil Hat's direction. This book is worth $5 for the new Fate concepts and artwork alone.
[5 of 5 Stars!]