We have the Americas, Europe, Africa and Asia all represented within the game. And while I agree that more american nations or asian civilisations would be great, there is one entire continent missing from the entire AOE series:
Australia and Oceania. I hereby propose a DLC that represents this yet uncharted part of the world.
The DLC should add 2 main factions:
The Aborigines - Australia was colonized during the late 18th century, somewhere between 3ook and 1m Aborigines lived there. Whilst many perished by disease there was also some armed conlict between the british and the natives.
The Maori - The Maori were deemed a warlike people and fought many battles against the british. They had a population of around 250k. New Zealand was eventually colonized during the 19th century,
The DLC could feature 7 new maps - 4 maps on the australian mainland, new zealand northern and southern island and tasmania. Many unique animals such as Kangaroos, Emus, Tasmanian Devil, Kiwis could be added. Minor Civilizations could include Tasmanian Natives, European Whalers and more.
