Portable addiction!
Basically, you start of as one of many different civs to choose from, each one with a different asset. Since I'm military-minded, my favorites are Germans and Mongols; the worst are Americans and Indians, as they are more culture-oriented.
Anyway, you progress through 4 different time periods, ranging from 4000 BC to around 2070 AD, and there are four goals to choose from: Space Exploration, Culture, Economy, or World Domination (my favorite). There are also levels of dificulty, so the game is easily playable by almost anyone. I would advise everyone to try a game at the easiest level first, though, just to get the hang of the game.
The best part about the game is its replay factor. If you are trying, as I am, to get all the gold medals in all categories, with all civilizations, at all difficulties, you are looking at many, many hours of playtime. And with this game, playtime = fun!
i would recommend this title to any strategy lover, and of course to all sim players. It lacks in nothing except maybe better graphics, but you will be having too much fun to really notice that.