A friend of mine calls this game the "Marx was right simulator", and he has a point. The game models 19th century capitalism and imperialism really well, and also models the ethnic makeup of any province in the world and accompanying nationalism accurately. Basically, it is almost a politics simulator.
Why does my friend call it what he does?
Because by late game, most markets will be flooded and there will be continuous crises of overproduction -- giving rise to a lot of communist agitation and frequent communist revolutions. But that's part of the game's fun too!
I've yet to play a strategy game as deep and complex as this one. Though as is true with other Paradox titles, combat is left up to chance. But that's more than made up for by the fact that you can conquer the world as sapient polar bears. How cool is that?).