Empire Earth is general good. Although, It will never reach Age of Empires.
You have the ability to start from the humans technical beggining, Stone age. It's limited what you can make and do, but as you advance through the ages, you soon recive a hugh number of abillities.
The game is good, and so is the histories, but...
One problem is, that if you've played Age of Empires (2) alot, you'll might have a hard time accepting the stories in Empires Earth, some of the stories seems just empty.
Another problem is that you sometimes ends up with old troops from bronze age while near modern age. So remember to make sure you upgrade all your units, else, there's a long way of upgrading in head of you.
The last problem is that before advancing to new ages, you might have to make a town center, or another mission. It's not that bad, because it helps you expand your empire.
But when all comes to one, Empire Earth is a damn good game, and you simply should give it a try, even if you prefer Age of Empires.
Through the game, you experince, Stone age, the Roman Empire, World War I and II, and even the future.
So don't be shy, Empire Earth will surely entertain you for months, might even years.