This looks amazing, I can't believe there's not more comments. I think the layout is great, very appealing, and easy to read (and the color scheme is very fitting). If you're still developing, I can take a closer look at spelling and the like.
Pros: The extensive Background chart, clear and concise rules, mutations, vehicles and upgrades, Zone/Enclave/Faction generators.... everything is great.
Cons: Missing some art (green squares) and some is pixelated (vehicle section), blank pages (you're probably working on filling those), In Mechs and Monsters, there are no robots.
I'll give it deeper read and comment more, in the event you decide to develop this further.