What's Duality? Duality is an open source, Windows-only 2D game engine based on OpenGL and written entirely in C#. Despite being a non-commercial project, it is a rather mature product because it has been around since 2011. It has also proved to be capable of delivering professional games. Obviously, the feature bucket is somewhat limited compared to the major proprietary engines. On the other hand, this fact makes Duality an excellent learning tool, because the user often needs to implement logic on a lower level and also has the opportunity to inspect the source code of the engine. Thus I would recommend this engine to game developers with an intermediate skill level, who'd like to have a take on open source and are not afraid of learning by doing. It's likely that anyone who has used Unity GameEngine will find it familiar as it is the source of inspiration for this beast. So What Is It In Short? It's an extensible 2D game engine. It comes with ...