Empire Earth was developed by Stainless Steel Studios (Founded by Rick Goodman, that guy who more or less invented Age of Empires), but they broke up with Sierra after that. Even the Add-On was not developed by them, it was made by Mad Doc Software.
After Empire Earth, Stainless Steel Studios started working on Empires: Dawn of the Modern World, which was released two years later.
It is more like Empire Earth as Empire Earth 2 was and if you didn't heard of it you should try it
![Smile :)](./images/smilies/icon_smile.gif)
GOG recently released it, now working on Windows 10.
Sadly the multiplayer is not working yet. But they say they are working on a fix.
Maybe neoee.net could release multiplayer for it, as it is the same engine.
Even 21:9 work, but your FOV gets smaller, I don't recommend it:
http://i.imgur.com/q7K8BZU.png
http://i.imgur.com/wiLEDqp.jpg