is a part construction and management simulation, part roguelike, indie video game created by Tarn and Zach Adams. Freeware and in development since 2002, its first alpha version was released in 2006 and it received attention for being a two-member project surviving solely on donations. The primary game mode is set in a procedurally generated fantasy world in which the player indirectly controls a group of dwarves, and attempts to construct a successful and wealthy underground fortress. Critics praised its complex, emergent gameplay but had mixed reactions to its difficulty. The game influenced Minecraft and was selected among other games to be featured in the Museum of Modern Art to show the history of video gaming in 2012.