the only bad thing about this game is that it gets so tedious later on when you have a huge sprawling empire with pollution everywhere.
I actually like the 'tedious' parts about the game, and IMO pollution is one of the most controversial feature in the game. But I think clearing a bit of pollution is no hassle.
Or, if you're really a sucker for strategy, you can get addicted in a few hours at a friend's house.
With a lot of games I was addicted to the demo but when I played the full version the addiction was gone, not that the full version was not as good. It was just that I played it too much and then got bored of it. An example of this would be... Starcraft. This doesn't seem to be the case with civ for me, though.