ExtremeEngine is a open souce game engine with C# scripting thats writen in C++ & C# with HLSL and GLSL shader support can be used for 2D and 3D. The engine itself using Vulkan for rendering becouse it's cross platform(And supports VR!).
The engine now is on devolompent and will be a public build soon as possible (:
The newer BETA version:
The old BETA:
