They've more than doubled their original goal, so check out the stretch goals and extras.
From the campaign:
The end of the world can be fun!
The most common theme of humanity is our ability to adapt and survive. That's great, because another theme of humanity is self destruction and war. Everyone has their favourite classic Post Apocalypse movies. Mad Max, A Boy and His Dog, Soylent Green, Logans Run, Cherry 2000, Tank Girl, 12 Monkeys. Waterworld. It's easily one of the most varied and creative settings ever. Our fascination with the end of the world produces great movies, great books, and very great games. It's the goal of this Kickstarter project to create a comprehensive and high quality tabletop role playing game that uses this setting. I want to make the end of the world fun.
Broken World is based off the RPG fantasy system called Dungeon World http://www.dungeon-world.com/. It's an Open Source system which encourages others to build off it and make their own content. I've done so with extensive edits and new systems that allow players to experience a dying world instead of a fantasy one.