Imagine Dungeon Keeper. Now imagine that the imps were dwarves. Finally, imagine that you only had imps, and everything else you met would try to kill your imps.
That's Dwarf Fortress. There are other small differences, like the fact that you can't slap your lazy minions with a virtual hand to make them work faster. You can drown them, though, or lock them in their rooms.
The game is hard, unforgiving and probably unwinnable. Fortunately, losing is fun.
The game is almost revolutionary in the things it has already incorporated. It already generates geographical and political worlds with bit of history and populates them, generates areas based on rainfall, temperature etc, has a bodyparts system which allows for some gory descriptions, has information that's mostly unnecessary (to make steel: mine hematite, smelt it with charcoal made from wood, smelt iron bar with some limestone and charcoal into pig iron, smelt another iron bar with the pig iron and piece of limestone and two pieces of charcoal for a steel bar - or die before you find anything but galena, silver ore), forces you to get food, water and lodging for your dwarves but sends in nobles whose demands make the other dwarves insane (and penniless and starving) just when you started to like them... Insanity includes berserking. Nobles whose demands AREN'T fulfilled go insane and kill the working dwarves (at least those of them who the Sheriff hasn't thrown in jail for ignoring a noble's orders).
It is still in Alpha, and as said, even if you can't win it, you can enjoy it. The game runs on Windows, and can run on Linux under Wine (at least). Unfortunately, Macs aren't supported yet.
The game itself:
http://bay12games.com/dwarves/screen..._building.html
Some screenshots:
Geographical map of the world. WARNING, 700+ kt.
http://bay12games.com/dwarves/screens/world_map1.PNG
Here the seven dwarves are getting ready for their journey.
http://bay12games.com/dwarves/screen...e_journey.html
The beginning: a wagon and the dwarves standing in heavily-forested mountainside:
http://bay12games.com/dwarves/screen..._at_cliff.html
Here the area just outside the cliff is already cleared of trees, the first few building are up and stone stockpile is already filling up. Carpenter is on his way inside, and his trusty but useless-as-of-yet mule following him. Inside, a rudimentary meeting hall has already been constructed and a well has been mined to its center; north of the hall are the first few quarters reserved for the dwarves, while there's a small room fit for industry in the east, as well as some dark stone (jet, onyx or obsidian) to be mined and used for crafts to trade for food before the winter comes.
http://bay12games.com/dwarves/screen..._building.html
Oh, and the game uses extended ASCII graphics. That's a good thing. I wouldn't like to see HOW, exactly, my hunter who ran out of bolts managed to severe that poor fox's left hind paw from its body, or how long the animal suffered when he forgot the animal existed. Or how, exactly, an extremely strong Legendary Engraver unskilled in the art of Wrestling managed to severe the head of a berserking Craftsdwarf. Or what an obsidian crown menacing with spikes of Tin and decorated by pictures of rats in Opal looks like. Not to mention the Flint trumpets!
P.S.
There's a reason for me not posting this before Dom3 had gone gold. This is quite addictive. I'm not sure if this particular addiction one wears down before October, but that's not necessarily a bad things, is it?