One of the strongest concepts that has come up time and again in my studies with various Indigenous groups has been that of "community". But thinking globally, this is probably similar in most cultures. Community is what makes a culture, and the best way to disrupt a culture is by destroying it's community. This is actually one of the definitions of genocide, and part of the ongoing issues faced by Australian Aboriginal groups even now.
Australian Aboriginal communities know each other by how people link to one another, in this context you introduce yourself by who you know, and how you know them or are related to them. The closest analogue I can think of as I'm writing this is the Ancient Greek world, where people would be identified by their home city and their position within that city. I'm thinking of my reading of Oedipus here, and a few other texts, but I know I'm missing key elements in my description.
Creating a game like this without adding elements addressing community, or rebuilding community, would be like developing a game about revealing the mystery of the unknown but only including combat systems. Whether this means the game will use relationship maps, or some other system to integrate social and emotional connections, I'm not quite sure yet. I'm a bit inspired by the way the Cortex system (particularly Smallville and Marvel Super Heroes) tied relational mechanisms into the core of the system, but we'll see where things go.
The other important elements that need to be be fundamentally integrated into the game are connections to the land, and connections to the story of the world (which might be another way of saying a connection to the Dreaming). These three forms of connection anchor the character's in the world, even as they move through it. As they transform the world (for the good or ill), they will similarly transform themselves. Afterall, traditionally a walkabout is a rite of passage, generally though from childhood to adulthood, but also marking a break from one stage in a person's life to another. There is a vague reflection to the hero's journey, with a voyage to the unknown, an acquisition of wisdom, and a return to the known. It's a tradition that is a distinct part of the various Australian Aboriginal communities across the continent, a part that linked communities in a vast network of knowledge and trade, and a part that has been actively suppressed by the colonial and western governments that have claimed the region. Renewing the Walkabout is symbolic of renewing the world.