Anything you discover is unlocked for your entire civilisation, rather than you having to stomp up the tech tree on each level. Survivors of the battle will be available on the strategic map to either garrison the new area or form the core of your onward-marching army. Similarly, any buildings you've constructed in an area will remain if an AI player invades. Many developers have tried to reduce the amount of dead time any RTS game starts with while you're building infrastructure, but few have gone nearly as far as Empire Earth.

Battles are more than straight skirmishes too, sub-missions spawning as you enter an area, depending on the current situation (which area it is, your tech level, what the prophets read in the open belly of a goat). For example, near the start of the game a local tribe might have their princess stolen, and you can rescue her to gain their allegiance. As you progress, you'll increasingly be given missions on the strategic level, such as conquering three of a faction's provinces to precipitate Empire Earth's equivalent of the collapse of the Soviet Union.