Open source library for creative expression on the web, desktop, etc.
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
A dead simple 2D game engine for Go
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Cross-platform game engine in Rust
2D Game Engine
Cross-platform 2D and 3D game engine
Real-time RPG for PC/tablet/phone; multiple quests and random dungeons
The Atomic Game Engine is a multi-platform 2D and 3D engine
online 4X browser game engine
Open-source, cross-platform, C++ game engine for creating 2D/3D games