I love this game! Developed by a Native writer who was tired of seeing endless fantasy worlds modeled on mediaeval Europe, and "tribal" peoples of any kind exoticized or treated as inferior, it's a post-spiritual-apocalypse world where all the cultures are inspired by various indigenous societies from our own world rather than by the usual Eurocentric fantasy tropes. But they're still fantasy societies - none of them are 100% identical to any real-world culture, and there are a lot of very imaginative touches, like an Aztec-inspired culture worshipping (and literally building their cities on) sanity-shattering Lovecraftian sea monsters, a Bedouin-inspired society that has developed sort of proto-steampunk technology using volcanoes as forges, plains nomads who ride giant spiders, etc.
It uses the FATE system, which is a nicely streamlined and easy-to-use system that will be familiar to many people from other games like Spirit of the Century, although things get a little complicated when you get into magic (I recommend going with the simplified magic rules that appear in a sidebar). So it's relatively easy to get up and running with quickly.
Be aware that it is a post-apocalyptic game (though set in the wake of a spiritual/magical apocalypse rather than a technological one), and can get pretty grim and dark - more so than I was expecting when I bought it. But at the same time, the spiritual themes running through it and the focus on holding onto hope and trying to heal the world make it ultimately feel uplifting.
Really, the only down side is that the book (and the Red Dog, Hungry Dreams supplement also) could really have used a good editor. As other reviewers have noted, there are a fair number of typos, minor rule inconsistencies, etc. sprinkled throughout it. Also, the history/cosmology section is really long and in-depth - enough so to be a little overwhelming - so that could have done with being tightened up a bit. But those are pretty minor quibbles with a game this fascinating. (I'm half-tempted to volunteer my services as an editor for any future books, just because I love this game enough to want to see it get even better!)
Overall, highly recommended!