Take the chess graphism, and use it with a chess engine.
Classic backgammon in fantasy setting with a lot of missions.
A Java chess engine using xboard protocol
Version 1.2
A free ActionScript 3 library designed for developing 2D Flash games
Cross platform administration tool for Source Engine dedicated servers
Pygrid is an open-source and cross-platform pygame/python 2D engine.
Vehicle simulation with freedom of movement on large map (5x5km).
A multiplatform game engine for interactive fiction experiences
A world editor for HGE game engine written in python and uses OpenGL.
A Java-based tactical RPG created for a high school project.
A 3D, fully concurrent game engine
Simple football match engine simulation
Open Source WW2 Multiplayer RTS
Free Android 2D OpenGL Game Engine