Terraria - Dig, Fight, Build! The very world is at your fingertips as you fight for survival, fortune, and glory.
Minetest - Minetest is a near-infinite-world block sandbox game and a game engine, inspired by InfiniMiner...
The Blockheads - Night is falling and your blockhead is freezing.
Infiniminer - Infiniminer is a multiplayer block mining game with several different player classes to choose from.
Clonk Rage - Real-time multiplayer game. Players can download more than 47475 maps at ccan.de
Voxelands - The Fun-Focused Free Software Voxel World Game.