The premise of this game is veeeery simple indeed. Seven factions have crash landed in a weird Earth-escape-pod-thing, and the leaders of them all want to get more power than the others. If you like your strategy games to come with huge novels containing the backstory of everything ever, there's one on the official website. Otherwise, you can just dive straight into the action.
The winner is the faction that achieves one of a few goals, including killing/conquering all of the other faction leaders' troops/bases; making a lot of money (or Energy, as it's called); and discovering everything there is to discover, science-wise. Obviously, the ideal party to do this is yours, but some very good AI, in the form of your opponents, thinks otherwise.
There are lots of things to tinker with while you're playing, my favourite being the Workshop, where you can create entirely customised units to serve you with the technology you have at your disposal. This can add a whole new level of fun to the game if you have plenty of technology and a mind as demented as mine.
The multiplayer mode supports many different methods of inviting your friends to join the fun, from taking turns at a single keyboard (hot-seat, as we call it in the Loop) to connecting via the internet to your opponents. If you're the kind of person who likes the odd quick multiplayer game, though, look well away from the multiplayer option in THIS game. Strategy games like this can take hours to play, though, if you're prepared to give up so much of your life, you'll be happy to do so because this game, for want of a better term, rocks.
The sound is amazing in places, although the music (or, rather, the lack of music) annoys me. This hasn't reduced the score I'm giving it because it can easily be sorted out by listening to your own music (run Winamp in the background or put on a CD).
Sid Meier's Alpha Centauri is a great game... IF you're into this kind of thing. I'm praising it a lot here, but thats because I find fun in commanding fictional armies and playing around with features/options. Want a quick action-packed funfest? Go away. Want an involving, addictive and very very cool strategy game? 5 out of 5.