Here is a short summary and my opinions.

-Summary-

-Campaign
You control 1 of the 17 factions over the time periods of the early medieval times to pre-renessance(s?). The factions are Russia, Sicily, The Byzantine Empire, Turkey, and England, this includes all the northern European factions. You also control Southern European Factions and The Egyptians, Moors, and the other Desert Dwellers. Also you can command the Aztecs. I don't know them all by memory. You start out with the original regions the country had in real life. If you are a Catholic faction the pope will give you missions you can complete to gain favor and rewards. Eventually one of your priests may become a Cardinal and then a Pope. If you attack another Catholic faction you will be excummunicated and the other Catholic factions will be able to attack you without fear of excummunication. You are also able to go on crusades, or if your the desert dwellers, a jihad. You start out with militias and small units of cheap warriors. Eventually you will enter the late ages and will have huge armies with knights covered in plate armor and cannons, and musketeers.

-Other Single Player
You have the option to play a historic battle, a quick battle, or a custom battle. Historic battles are scenarios that are already set up for the player to complete. Quick battles are randomized battles that the computer sets up. Custom battles let you choose where you fight, the weather, the season, the time, and if there is a type of cizilization. You choose the amount of money you get to select units from a certain time period or all time periods.

-Multiplayer
This isn't the best I've ever seen. It's great if everybody playing has a nice gaming rig and no connection problems. Usually people will spam Elephants which are next to impossible to kill. Before the game begins there is a 85% chance someone will have a bad disconnection and end the game. But when you end up playing it is fun and easy to make friends. Overall, I say it isn't the best but it certainly isn't the very worst.

-Gameplay
This game is great for tactions. It realy challenges your brain to make up the best strategy to win. It also has two worlds in a way. One world is the turn based campaign mode. The second world is the RTS style fighting. If you ever played Rome Total War this will be very similar.
The Armies are huge and may cause some lag. Special abilities make the game more fun, like exploding shells, wedge formation, and flaming arrows. But if you have a slow computer the gameplay will be super slow. It does warn you when you may have to many units for your computer to handle.

-Visual Appeal
Graphics wise it is great. There once again are better, like company of heroes. But this game is only a step down. Individual units have killing animations, so while a dismounted knight may kill an Aztec warrior by just stabbing and moving on, another knight may stab it and then thrust down with his sword. The terrain detail is nice to. Large castles and small towns, they are all greatly detailed.

-Final Thoughts
I think this is a great game. Overall I would give it an 8.5. I would recommend someone to buy it. Unless your computer sucks, then stay away. It is fun to zoom in on the action to witness the detailed soldiers fighting and killing eachother, then zooming out and taking in the whole thing at once.

Hope this helped. Here is the official website. http://www.totalwar.com/