Dwarf Fortress - Dwarf Fortress is a single-player fantasy game with two modes: fortress and adventure.
Banished - As always, Email support (at) shiningrocksoftware (dot) com if you have any issues. This will likely be the last update of Banished, except for any major bug fixes. The OSX and Linux versions development has stopped, and won't be released.
RimWorld - RimWorld - A sci-fi colony sim driven by an intelligent AI storyteller.
Minecraft - A block-building game that allows you to create and explore entire worlds from scratch.
Terraria - Dig, Fight, Build! The very world is at your fingertips as you fight for survival, fortune, and glory.
Castle Story - The creative voxel-based strategy game in which you explore floating islands, architect epic castles, and defend against hoards of enemies with your friends!