Fortress and Adventure mode are fun and all that, but one of my favourite aspects of the game has always been world generation.
I came into DF thinking it'd be just a generic fantasy world simulator. Creating a world where everything was finalised after said world was complete. Dead and static.
Nothing could have prepared me for this.
It's just a thing of beauty, when you think about it. I like to think of the game searching parallel dimensions, testing and checking for the perfect world, bringing it into existence right before your very eyes.
Then you sit there and watch. Watch as civilisation fights to conquer the wilds. Watch as towns and hamlets grow into cities and capitals. There's nothing you can do to influence it. All you can do is wait, an almighty bystander in the proceedings.
Then, once time has run its course and the clock stops ticking for just a moment, you get to admire and savour the land. It all feels so real, so alive. And as you survey the land, you stop seeing it as a bunch of symbols, and begin viewing it as a living, breathing land. Cities bustling with activity, mountainhomes buzzing with industry, elven retreats... existing.
You notice the little intricacies of the civilisations. Several human towns connected with a dwarven mountainhome; a catalyst for trade, perhaps? Hamlets clustered about a town, each of which is clustered around a capital, a close knit family with its own dark secrets.
And it's these little things that lend you a sense of realism, of duty, when you play the game proper. You cease to think of it as a game, but more of as a world you are a part of. Influencing and shaping its history with your feats and failures.
Nothing could have prepared me for this when I downloaded the game.
And I'm glad nothing did.