Open Source C# Game Engines

San Andreas Unity is an open-source reimplementation of GTA San Andreas game engine in Unity. This won't be a complete reimplementation, but the focus is on gameplay features, multiplayer, and creating a framework that will allow easy game extension and unlimited modding possibilities. When running for the first time, the game will ask you for a path to GTA installation. You need to own GTA in order to play it. The game is tested on Linux, Windows, Mac, and Android. It supports both Mono and IL2CPP scripting backends, so it can be built for any platform that Unity supports, provided that you can copy PC version of GTASA to target device. Game fully works in multiplayer. You can start the game as dedicated server, as a host (server & client at the same time), or you can connect to a server. This works on all supported platforms, which means you can start a host even on Android device.

Stride (formerly known as Xenko) is a full-featured, open-source game engine written in C# and targeting the .NET ecosystem, designed for both 2D and 3D games — and even VR experiences. Stride offers a comprehensive toolchain: an editor for scene building, asset management, a rendering pipeline with physically-based rendering (PBR), and support for advanced graphics features such as real-time reflections, post-processing effects, and complex materials (skin, hair, cloth, etc.). Because it’s built on modern C# and .NET, developers can take advantage of modern language features (C# 14, .NET 10), tooling (Visual Studio, VS Code, Rider), and long-term maintainability. The engine supports cross-platform development: you can build for desktop, mobile, or VR, and target multiple operating systems. Stride is modular and customizable: you can tailor rendering, physics, scripting, and other subsystems to suit your game’s needs.

KSFramework is a Unity3D Asset Bundle development framework that integrates KEngine, SLua/XLua/ILRuntime, and provides a set of auxiliary tools for programming, art, planning, and operation. Vika table vika.cn , API-supported data table, perfect real-time collaboration, can be used in 1000+ scenarios such as silky project management, game planning configuration table, data sorting, etc. Hot reloading is the development focus of KSFramework - without restarting the game, reloading the code and configuration table can immediately see the modification effect, maximizing the speed of development and debugging, and facilitating hot updates during the operation phase. For programmers, basic function modules such as AssetBundle loading and packaging, scripted UI, automatic generation of configuration table code, download and update can be used, which greatly reduces the workload of basic functions around the game.