http://survivorsofragnarok.com/It could charitably be described as "Dwarf Fortress but with a side view", or perhaps more accurately a combination of Dwarf Fortress and Terraria... Or perhaps just "Terreria but broken and with dwarves"..
Got it in an early indie alpha bundle and was pretty excited about seeing where it would go.. But it doesn't appear to have gone much of anywhere unfortunately (hence it's inclusion in this thread).
I got it quite a while ago and booted it up a month or so ago to find that seemingly little had changed, though at least it crashes slightly less frequently now.
Really the fact that these are mostly indie games mentioned shows how great the concepts of the games are.. After all (As jokingly mentioned earlier) Dwarf Fortress would have died long ago were it not for the excellent and original concept that keeps the community around (both to donate money and to spread the word to others). Realistically, while it has been updated quite a lot, it is not radically different than when I started playing it years ago (and that was years after development started) and playing it with no modifications or utility programs of any kind results in a learning cliff and a lack of interesting* content.
*There is tons to do in the game, but most of these things are small, such as being able to make clay pots instead of wooden barrels. That's great to add depth, but it's hardly a reason to keep playing. Were it not for mods like Masterwork, fortress defense, etc I don't think I would keep coming back.
Contrary to the popular opinion, in Vanilla once you get the hang of the crazy UI and some of the general concepts of the game 'winning' (or at least having a completely self-sufficient fortress nigh invulnerable to all enemies is pretty easy, even without things like walling yourself off. After that it's just waiting around until the FPS drops to zero.
I love the game and see amazing potential in it, but realistically it would probably belong on this list.