Maybe it's because of nostalgia, but the game's really good, I used to play this all day when I was a child. Think of it as Age of Empires that begins in prehistoric age and goes up until the robotic age. There are planes, helicopters, nuclear weapons etc. in late game and it's so fun. There are also (single player) campaigns, Ancient Greek, Medieval English, WW1-WW2 German and near future Russian. The Russian one is especially good, has a nice story. The only problem with the game is its AI in normal single player games. The AI feels much more powerful than you and they rarely fight between themselves, at least in my case.

Empire Earth is propably the only one RTS game I truly appreciate.

It looks and sounds still pretty good and plays really smoothly in all aspects.

But the selling point of this is the appeal to guide your little civilization from the stone age all the way to the space age.

This was such a cool concept and it was actually heartwarming to see the continous rise and grow of everything you have built and nurtured here.

This was always the true appeal of Empire Earth for me.
The campaigns were great sure, but nothing could be beaten by just starting a random match aganst whoever and simply see how much ages you could plow your people through this time. That was oddly satisfying.

Even if you are not into RTS at all (like me) still give this a shot if you have a thing for the history of the human race.

Chances are that you will not regret it :D
You can get Empire Earth on GOG ^-^