On a more general level, you get some new units and civilizations, and you can tick a few boxes to create your own rather than using one of the pre-made ones. Some tweaks have been made to the graphics and to the game mechanics, such as the one enabling regular grunts to become heroes, but it's very much the same old stuff as before. Yawn.
Supremacy? Hardly. Fans, enjoy the second helping of EEII. Everyone else, head onward and upwards to brand new conquests.