I own a box copy, and boy, the bugs I've encountered. Building units, but not having them appear. Surrendering a battle by withdrawing your army, which results in your army being destroyed, but the battle won. Ships that don't move across the screen, but stutter from place to place, not due to framerate issues, that's simply how it works.
It is a shame, because I really do like some of the ideas in here. I was a fan of EE1, but not EE2. I liked the idea of having 3 sides that were completely different, instead of 20-something civs with one unique unit each. And the world-domination campaign would actually work for this game. You conquer several provinces with your tribes, and by the time you're bored with that style of fighting, it's time to tech up and fight with all new units. They put quite some ideas of bonuses you can pay for on the world map.
Unfortunately, someone forgot to playtest this. The AI is poor on the battle map. On island-maps, once you conquer a province, it's yours forever. Invading AI armies generally need 10 minutes to figure out how to unload the troops on an island. By then, you have enough units ready to wipe them out before they can even begin building their base. You could even try to sink those transports before they unload, but that's unlikely. Ship sight range and turn speed are so low, a moving enemy is generally out of sight before your ship can get a shot of, and your units instantly stop their attack orders once an enemy leaves sight.
Things get worse on the world map. You have a whole list of upgrades, but hardly any are usefull enough to justify their cost, when compared with spending your few recourses to buy a few more armies and steamroling the enemy. Worse, the enemy has very low priority on advancing to the next age. If you have a lead of 1 age, you have an advantage. If you have a lead of 2, you generally don't need to build a base anymore. Just the escort guards that you start the mission with can wipe out the entire enemy army and base, if you play your cards right. And the AI has no problem letting you get to the last age without aging up at all (or maybe once, to the middle ages) All my campaigns have ended with me using lightning-shooting gunships, invisible hovercrafts, supertanks and blackhole-creating robots against empires who fight back with bows for the last 15 battles, and that gets boring really fast. The only times I ever went up against gun-wielding enemies in the campaign was either during the special scripted missions, where an appropriate enemy spawns for you, or when I didn't pay attention, and the enemy captured a few of my units with monks.
I've went and played it for some time anyway, and each time I'm again disapointed with how poorly this product was supported. With a few decent patches, the basis of this game would have made me love it. But they put out one launch-day patch, and then stopped paying attention. Such a pity.