This is a sketchy concept sheet for a hypothetical Australian civilization that could be added (or modded into) the game Age of Empires II (specifically the HD version you can download on Steam).
The Australians would have as their unique unit the Boomeranger, a fleet-footed huntsman with little armor but high movement speed and an attack bonus against cavalry (since the boomerang was traditionally used as a hunting weapon). Although the Australians would be able to build fish traps at the cost of 50 stone (instead of 100 wood like most of the game’s other civilizations), and fortifications such as Castles and Walls would cost much less stone, they wouldn’t be able to build Farms or Stables (so no cavalry). However, their unique Dreamtime technology would allow Monks to “convert” any wild animals that are capable of an attack.
Finding a unique Wonder for the Australian civilization was admittedly tricky. Although some Aboriginal societies in southern Australia did build stone houses, I am not aware of any Aboriginal structures that would register as “monumental”. So I opted for the natural rock formation known as Uluru or Ayers Rock. As far as the Australian civilization’s architecture set is concerned, I chose the African set introduced in the African Kingdoms expansion since it seemed the least awkward (and its brown color scheme would best suit the deserts and savannas of much of Australia).