This game is so good , it will be adicted for the next 5 years or so.
It looks more like Civ3 but over its a grealy improoved game.
new addons that make this game more enjoyable is , advanced resource system , religions , more terrain and like in all Civ games , a big thec chart.
This game is very flexible , you gave make the romans be concuered by the greeks , the germans using Comunismnor the Americans taking over the world with nukes.In short you can do anything you want.
If you do a whole scenario from 4000BC till 2050 AD and finish it (it will take like 25 hours to finish it) you will get sort of bored with it. But like after 2-4 weeks later you will want to start from the begining again because it has soo much to offer.
Over all , Civ4 is an exelent game recomand the buy for anyone who like games.