Terraria - Dig, Fight, Build! The very world is at your fingertips as you fight for survival, fortune, and glory.
Gnomescroll - Gnomescroll is a multiplayer survival RPG in surreal environments.
The Blockheads - Night is falling and your blockhead is freezing.
Epic Inventor - I have said a few times that Epic Inventor was inspired by Terraria.
Clonk - Clonk is an entertaining, action-packed game of strategy, tactics, and skill.
Star Sonata - Free to play space action MMO.