Dwarf Fortress is an amazing game. I mean "amazing" at the level of Sim City and Civilization, as amazing to encounter today as they were when first released. I'm not sure I can offer higher praise.
And yet--it is also frustratingly difficult to get into, and utterly obtuse in terms of its UI.
Dwarf Fortress is a game from an alternate universe. Clearly, no one in his right mind would have created it in our own. I deduce this from its main characteristics, and I think can very clearly describe the alternative universe it came from--let us call it "Earth B."