The lowdown:
One of the few major complaints levelled at the original Age of Empires III was the odd way that Native Americans were handled in the game, where they played only a minor supporting role. Apparently they were saving themselves for this expansion pack, which includes three different tribes: Iroquois, Sioux and Aztec. Each has a very different set of units and buildings, both compared to the European factions and each other. The expansion also includes new hero units for everyone, new minor tribes (for a total of 16) and a new victory condition called Trade Monopoly where you have to take control of your opponent's trading posts.

Most exciting moment:
The most unusual of the three new factions are the plains dwelling Sioux, who are master horsemen and do not need to build houses in order to create more troops. This makes them a highly unpredictable enemy and perfect for hit and run attacks.

Since you ask:
One of the most interesting new features for the European faction is to call for a revolution. This stops all your production for the rest of the game but instantly upgrades all your military units and turns all your civilians into soldiers. It's a big risk but often the only way out of a tight spot.

The bottom line: A solid expansion to one of last year's best strategy games.-HARRISON DENT