Open-Source Classic Tetris
Game's list fixer.
Open source rewrite of Heroes 3 engine
An adventure "Legend of Zelda"-ish game
TurboSphere is an easy to learn and powerful JS based game engine.
Battlecache Planner Application
Library for creating turn-based games with simultaneous moves.
Adventure/RPG-Gameengine + Game
Dots and Boxes for 6 players / Käsekästchen für sechs Spieler
Tower Defence
Fast paced action RPG with retro graphics style
Just another online poker software, but open source for once.
A Java chess engine using xboard protocol
Linux on iOS via iDOS
Classic backgammon in fantasy setting with a lot of missions.