Shortest, most elitist answer: there aren't any. The style of play we have vaguely seen before (cough, Sims, cough), but the depth (and other features such as being able to shape the terrain completely to your liking, something I have not seen since the early X-Com games) seems unparalleled, not to mention how well it lends itself to story-telling and, most of all, humour.
I use to refer to it as The Sims on acid
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In The Sims, you buy a new TV. One of the Sims is happy to have it, and then goes off to the swimming pool. Meanwhile a thief comes in and steals the TV. The idiots who live in the house never notice. In Dwarf Fortress, you end up with a statue of eels (which menaces with spikes of steel) because some random dwarf got possessed by unknown forces to run some poor mason out of his workplace so he could build one, then the guy who is responsible for placing it can't do so because he's fighting carp in the river, then goblin thieves waltz in and steal the statue, and the guy who made it gets so mad he has to be restrained by the sheriff and his battle axe and put on a leash in the basement while the resident artist engraves pictures of his tantrum in the royal dining hall, where the dwarves try to eat while the pets and livestock hold court on the tables. It's like being used to classical music concerts for then to go watch a black metal band.
On a more serious note, though, it has elements from both Sim City, The Sims, and RTS games such as Age of Empires II. I never played Dungeon Keeper, so can't comment on that. The fact that it actually generates a world realistically (complete with erosion, AI civs and individuals, etc.) and runs it as you play, letting you go back to your fortress with an army after it's fallen and whatnot, is pretty awesome, too.
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Topic: What mainstream game is Dwarf Fortress like? (Read 7634 times)