Yes, it's probably one of the best RTS games I ever played. I wasn't a big fan at first. What got me into it was Microsoft's free demo download. I liked the gameplay and involves a lot of strategy which kept me pretty busy. A really good game would usually take me a few days to complete. Online gameplay is even better because that can last for hours and hours plus, you get the challenge of not knowing what your opponent has planned.
It's better to understand the game first by reading up on the game itself. There are different civilizations you choose from. You lead your choice of whoever you pick (Russians, British, Ottomans, etc, etc.) and help them survive throught the ages in the new land (which is the Americas). In the meantime, other civilizations will be conquering different regions and trying to take over your land. You defend it and just try to dominate them by advancing to different ages while adding to your arsenal, new technologies, capabilities, friends such as local native indians, land resources, etc. I usually play the single player skirmish most of the time because I can save it and continue next time. When I have tons of time on my hands, I would go online and play.
Online play is fun. You go to a room and you can play 3 on 3 or whatever. You and your two other allies can communicate with each other on what you want to do, strategy wise to defeat your enemies. In the beginning of every game, you have to build up your resources. That enables you to build buildings, add to your military, advance in ages, explore new technology, etc. It's fun overall.