If you are going to play this game on a older computer then you will be suffering through a painfully low FPS.
The game has gotten a nice graphical overhaul, and is now visually impressive. Sadly though Microsoft did not optimize the game to the point of a Valve creation (for example Half-Life 2) so if you are going to play this game on a older computer then you will be suffering through a painfully low frames per second.
The single player is enjoyable to go through once, and the games artificial intelligence give the player a challenge. What really makes this game worth while how ever is the mulitplayer. With support for up to eight players, many memorable games will be taking place.
With each of the civilizations having a unique set of bonuses they truly feel individual. Each is played in a different manner, and are remarkably well balanced. With no clear cut winner players are free to choose the civilization that they enjoy playing the most. This leads to a better gameplay experience, and more diverse strategies playing against friends online.
Some of the flaws of the game is that this game favors those people who have money to buy a great computer. In contrast those with frame rate problems will have a hard time competing online. Another is the lack of unit formations in the final version of the game. This leads to a chaotic, and unorganized battlefield.