Cocos simplifies game creation and distribution with Cocos Creator
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
The Atomic Game Engine is a multi-platform 2D and 3D engine
3D .NET engine for Windows, Linux, Mac
Open-source, cross-platform, C++ game engine for creating 2D/3D games
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
PixelLight is a cross-platform application framework
Cross-platform 2D game engine