Open Source Game Engines

Longford is a 2D, Lua-based game engine for Windows. It has the following features: + Sprite hierarchy. Sprites drawn in order according to a display "tree" allowing grouping of complex drawings. + Frame update, keypress and (multi)touch events which propagate through the display tree. + Creation of Sprites including polygon Shapes and rectangular Bitmaps with transparency (import as PNG, JPG, GIF, BMP, TGA) + Creation of Textfields based on bitmap fonts. + Translation, rotation and scaling of sprites. + Box2D physics engine. + Play sound effects using WAV files and stream music using OGG files. + Automatic tweening system + Texture atlases so that many Bitmaps can be "cut out" of a single larger picture file. + Supports user-written shaders for advanced graphic effects. + Automatic resolution scaling. + Supports OpenGL or DirectX backend

Open Game Engine 2D is a full features and cross-platform 2D game engine. It aims to help developers to create 2D games with only flat files (such as ini and script files), so that games could be written once and played under any platform supported. This engine is a pure 2D game engine written in C/C++. It is base on SDL and AngelScript. So, it also aims to run in any platform supported by SDL and AngelScript, such as Windows, Linux, MacOS, iPhone, Android, Windows Phone, Symbian, NDS, PSP... But, in current version, the engine only supports the following platforms: Windows, Linux, MacOS, Windows Mobile, Android, iPhone.