It's certainly a very impressive game but I did find it disappointing in one regard. There's two distinct modes of play, Quick Battle and Conquer the World. Quick Battle is like a multiplayer game where you set up a single, stand-alone scenario. You choose how many other cities you want to play against, the map you want to play on and so forth. Or you can let the computer choose everything at random.
You could end up playing the Ancient Brits, fighting the Chinese on a desert map. There's no geographical or historical significance to the Quick Battles at all. It wasn't much fun after one or two games because when you conquer the other city the game's over.
The other mode is the Conquer the World and that's a bit better because it lets you play many scenarios in a campaign to conquer the whole globe, territory by territory. What I didn't like about this is when you invade a territory you are given Battle Objectives, like defend an already established city for fifteen minutes, or defeat the enemy city within ninety minutes, and sometimes you don't get to build a city at all. You have to conquer the enemy with the troops you are provided with at the start. What's fun about that? This ruined it a bit for me. It's a shame because it looks great but I didn't like either the Quick Battle because it's so much like playing a stand-alone multiplayer game, or the Conquer the World because often you don't have the freedom to build up your cities as you choose, or if you do you have a time limit.
I haven't read a single review that didn't rave about this game though, so it's probably just me.