As you can see there are options to play up to 11 players. Or if you want, just 5, or maybe 4.. even 3. And If you are feeling a little frisky, and want some more action ;) There is also two one on one scenarios in the form of the Northern Expedition, and the North vs the South.
You can also customize these games a bit. High Unit Density allows for more production, thus more units, and deeper penetration of the tech tree. There is a 2 round breather, that allows you and everyone else to relax, set up defensive positions, prepare for offensives and negotiate with others. There is an all at war option, that pretty much does what it says: Everyone will begin at war. There is also an option to geographically equalize some nations for the 11 player game, where Korea and Tibet probably has the advantage otherwise, being very isolated (in Tibets case) and easy to defend, compared to the rest.
But there is more... Once a selection for the number of players you want is made, the names of the different factions change to reflect the game type.