0 A.D. is a free, open-source, cross-platform real-time strategy game.
Cooperative multiplayer graphical RPG and adventure game
A free 3d game for PC that does not limit the player. Fight,Build,Gain
Open source FPS/RTS Game
Cross-platform real-time strategy game (3D)
The Clue! / Der Clou!
A complete 2D Game Engine with built in drag and drop editor
Mission based first person shooter