I'm currently working on chapter 5, the world of Saaruk.

Most of the experience takes place in a huge, impossibly prehistoric jungle island called the Cradle. There's no map for this place, and even the characters who live here haven't explored every corner of it. Much of the island remains shrouded by mist and danger, with most of the roleplaying taking place in the "heart" of the island where the Saaruk live.

The Cradle lies somewhere in the Pacific Ocean, although this far in the future no one really knows its exact location or history. I at first thought about making it like Pandora from James Cameron's Avatar, with skyscraping trees and floating islands, that type of thing... but since the setting is Earth, I figured that wasn't quite realistic enough.

Instead, the Cradle is kind of like a post-human Hawaii, turned into a volcanic rainforest due to vast ecological change and tampering from human scientists long ago. The island is filled with dinosaurs in a kind of "Isla Sorna" fashion (taking reference from Jurassic Park the Lost World,) and plants and animals here are larger and more dangerous than any you can encounter on modern-day earth. But the Saaruk themselves are instinctively attuned to these kinds of dangers. 

There are plenty of key destinations with important cultural meanings to visit, and the Saaruk have developed specific ceremonies and rituals that can take place there. One such place is the "Bone Arch," a towering pair of skeletal fossils from some extinct colossus, set against the backdrop of a volcanic spring. Characters can travel here to experience visions that might even be fragments of the future.

One design concept I kept from my toying around with "Avatar" is the idea of a "Presence," a kind of awakened Earth spirit that flows through the Cradle, and which players (and other living things) can tap into. The Presence is more ephemeral and vague than the Maia-like goddess of Avatar, but your character can use their connection to this entity via dreams and portents to gain bits of wisdom about the world, foresee dangers, or even communicate with wild animals.

Despite my interest in deep ecology and phenomonology, I didn't want the game to be too mystical, although the Saaruk and their culture have a lot of mystical qualities about them. In this chapter I'll have a full list of flora and fauna, including real and imagined dinosaur species and other animals, that you might encounter in the Cradle, and the kinds of problems (or solutions) those living creatures might bring to the Saaruk tribe.