Paintown is a 2d fighting game engine.
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
Educational framework for OpenGLES, OpenCL and OpenAL
A generic 2D engine for any kind of game
2D physics engine for games
C++ OpenSource Game Fabric based on SDL2
Visual Novel engine, editor and game development.
Free Android 2D OpenGL Game Engine
Java game engine for shoot 'em ups, using Java2D.
Cross-platform 2D game engine
OSGET is the first open source mobile game engine template.
Free MMORPG Engine. Develop and host graphical browser-based games.
Zap Engine