Overall, I enjoy this game. In some ways it has a lot of repeat play value, but the reason I didn't give it 5 stars is because it's not particularly exciting. In the end, there is no other thing to do than continue attacking until you can take over the whole world. There comes a point in the game where either you have a shot at doing it or you know you can't. At that point, the game become boring.

THE GOOD
1. Great level of historical detail for the major players
2. Many options for controlling your countries economy, military, and technology
3. Grand scale,
4. Many playable nations,
5. Real time

CONS
1. Hard to figure out (though once you do, it's not hard to play.)
2. Not as fun if you're not one of the major powers.
3. Complicated to manage air, sea, and land combat at the same time.
4. Many events are "locked" historically and affect things. For example, Poland is always going to get attacked by the Germans at some point.
5. Some countries, such as Poland, are not winnable.
6. It's possible to flush a huge amount of time into this game.

I play the Mac version. DON'T rely on the specs given here. I use a G4 1.67 with 2GB of RAM and this game runs adequately to poorly. There are no 3D elements or real animation to speak of, and the graphics blow, so it's either poorly coded or just that plain massive. There specs of a G3 500 seem just plain insane to me.