It would be great if you could start the game by "customizing" your people. You could put various points into characteristics similar to the classic attributes of a role-playing game:
Strength - determines the combat effectiveness of your military units, how many units you can build vs your population, and war unhappiness levels
Dexterity - determines your productivity levels
Constitution - determines how easily your people is assimilated when conquered
Intelligence - determines inventiveness, and hence the research rate
Wisdom - determines how easily the people fall into civil strife
Charisma - determines the how well your people like and are liked by other ethnic groups
As the game progresses, you would come to know the exact characteristics of peoples you have direct contact with, and have "approximate" knowledge of peoples you know of second or third hand.
This would effect gameplay in a number of ways. You might want to make greater effort to spy on countries with higher intelligence, and you might want to prepare extra defenses on the border of countries with higher strength. You might want to strike up alliances with countries with higher charisma, to improve your standing with other peoples. You might want to conquer peoples of higher strength, dexterity, intelligence or wisdom, provided they don't also have a high constitution (making them an unruly minority group).
The game difficulty would be determined by how many points you start with. You could choose to be assigned more or less points that the opponents, and that would effect your final score. For a real challenge, you could be a wimpy, lazy, easily assimilated, backward, unruly and ornery people! But to start you could be a battle-ready, industrious, cohesive, smart, easily managed and loveable people . .
