You can make it - Open Source MMORPG Platform
Game engine supporting many 3D/2D formats and graphic effects
PyCAPGE - Python Classic Adventure Point and Click Game Engine
Example code for creating a 2D platform game in Java.
3D .NET engine for Windows, Linux, Mac
.NET - VISUAL BASIC NVIDIA +ATI PHYSX SLIMDX DIRECTX 9 -ENGINE/WRAPPER
Mahasona engine is an open source game engine.
A generic 2D engine for any kind of game
Pygrid is an open-source and cross-platform pygame/python 2D engine.
A retro style video game engine for RPGs and adventure games.
Hungry Hero is an open source Flash game built on Starling Framework.
A lightweight HTML5 Game Engine
UtiliGame is a light-weight game engine written in Java.
C++ SDL/Box2d Programming