The Atlas book is fantastic. It's part Atlas, part bestiary and part optional rules.
The Atlas part gives a brief overview of every nation on the two continents on the map. Some nations get one page, others get from 4 to 8 pages.
The optional rules include low to no magic options, long term injuries, alchemy, pirates and ship rules, new Foci focused on the three basic character types (Warrior, Expert and Magic), and new classes.
The bestiary greatly expands on what's in the WWN core book.
His next game to hit Kickstarter is Cities Without Number, which will be mostly Cyberpunk.