Dwarf Fortress

Dwarf Fortress is an ancient machine able to create mini-universes inhabited by fantasy characters. It does this by draining the sanity of the player and anyone looking at screenshots or gameplay of it.

People with insufficient braincells to kill will assume the game to be a random scramble of ASCII characters and moving smiley faces.

Summary
In a time before time, Toady One The Great, a toad demon, created Dwarf Fortress to trick humans into making him a permanent part of this world. This was achieved by creating a game that can create fantasy universes on the go for the player to torment countless happless creatures. The torture and sense of sadism derived from the game fueled Toady One's power and made him achieve godhood in a short time.

Gameplay
Unlike most sane games, Dwarf Fortress does not actually have a winning condition. Every fortress, no matter how successful, is doomed to a hideous death at some point - in fact, in older versions of the game, the simple act of mining a certain extremely deep and rare ore would start a hidden timer condemning your fortress to certain destruction at the hands of a balrog standin, with the game sadly informing you that your dwarves dug too deep, but keeping your fort going long enough to strike that ore was an achievement in and of itself. This inevitability has lead to the fan base's rallying cry: "Losing is Fun!" In fact, in discussions on the topic, the word 'Fun' (especially with capital 'F') is entirely synonymous with 'Hideous Demise' and the things that are likely to cause it, with 'Hidden Fun Stuff' used to refer to the demonic late-game enemies and Hell itself.

The gameplay has an exceptional and frankly obsessive depth of detail. Despite being (by default) ASCII-based and extremely obtuse, like the old roguelikes from which it draws inspiration, huge amounts of information are tracked and considered for just about every aspect of the game - down to minute details such as the exact location and severity of injuries (first joint on left little finger slightly bruised, for example). Combat is complex and messy - a typical dwarven battlefield will be full of bloody stains, severed limbs, discarded weapons and crossbow bolts, and the vomit of the unforunate recipients of abdominal injuries. After-action combat reports give detailed and often hilarious or epic blow-by-blow accounts of the fights that take place, and the player even has the option of entering adventurer mode to explore their world and get in fights themselves, presuming they enjoy being shot by archers off the edge of the visible area.

Game modes
The game consists of three modes: Fortress Mode, Adventure Mode and a third mode (Legends Mode) categorising basically every event that ever happened in your world.

Also known as: Micromanagment From Hell, Babysitting Sim From Hell, AAAAAAAAAAAAAAAAAA and WHY AREN'T YOU RUNNING FROM THE 10 FOOT TALL FLAME SPEWING ELEPHANT DEMON!!!
The main course of the game and posterchild of modes. In this mode the player takes on the form of a omnipotent (well, omnipotent as far as the map allows you) observer leading a small group of settlers into the hapless wilderness to make mad cash and a cosy mountainfort to live in.

The amount of FUN that the surrounding can supply depends on where the player wishes to settle on the map. The factors counting towards this include: As mentioned in Gameplay, their really isn't any objective in the game except for survival and expending your wealth. The mere acts of setting up a decent brewery is the only thing you need to worry about as the hole you dug yourself in can easily be defended by a locked door or a 1 foot deep moat. The real JOY comes from the local monstrosities trying to end your greatness.
 * Natural savagery: This ranges from mirthful meadows (with murderous unicorns and elves),the mundane wilderness (with murderous dingoes), untamed wildes (wich is the same as wilderness except the local fauna is GIANT) and the haunted areas (where the local fauna will be UNDEAD if not GIANT. Oh, and corpses, severed limbs and any happless dwarf standing in the rain of blood will turn into undead).
 * Local factions: These consist from the always-hostile-goblins, elves (HA!), humans, other dwarves and ,if nearby, a necromancer tower. Goblins and necromancer will, on a yearly bases ,besiege your settlement. Elves, humans and other dwarves will send trading caravans but you can declare war on them by cleaving an axe through the skull of any diplomat or trader standing around.
 * Natural resources: like farmable soil, valuable rocks and minerals, a water supply (blech!) and local timber.
 * Your incompetence

Also known as: 100 ways to die as Frodo Baggins, Martial Arts Sim From Hell, Choose Your Own Adventure DEMISE
Of course, the game doesn't just generate an extensive world that would give J.R.R. Tolkiens an orgasm for you to only explore 1 square foot of. It also let's you roam around it as a dwarf, human, elf NO!, goblin or any sort of animal in the form of a beastman (like a SpiderMan that can wield 3 shields and 3 different kind of weapons).

The objective of this game is, again, completely up to the player. Most players will most likely dump all their stats into weapon and fighting skills as they venture of to slay the local fire-breathing mantis made out of clay but sometimes you just want to go around, explore and play music as a cowman with legendary dancing skills as you impress the demon-lord of a Goblin pit next town over.