One of my favourite all time games.
The reason, I am at Uni and 11 years after I got this game, I still go into phases of playing it nonstop completely distracing me from my work.
As you should know from what I just said, the game is incredibly addictive.
The variety of the game is pretty immense. Every map has its own challenges as does the way you decide to play your game. The technology research in particular is very flexible and is much more interesting than the other civilizations as the number of requisites needed for a technology is fewer than the other Civ games.
A particular highlight is the board of advisors- real actors telling you about your empire, its very funny and really unique.
I dont really need to tell you what the game is all about, all you need to know that even after so many years after its release, this game is very much worth playing.