RPG Maker 2000/2003 and EasyRPG games interpreter
HTML5 Phigros chart player/simulator
Open-source rhythm game
Aim assistance for blocks and mobs
An open source re-implementation of RollerCoaster Tycoon 2
Stream switch games to your PC via USB or network
Open-source Android/Desktop remake of Civ V
Set of Python modules designed for writing video games
Access GameLift resources and integrate GameLift into your Unity game
DOSBox Staging is a modern continuation of DOSBox
Doom-based AI research platform for reinforcement learning
Accuracy-focused XNA4 reimplementation for open platforms
Classic overhead run-and-gun game
Endless Sky is a sandbox-style space exploration game
Voxel game-creation platform with easy modding and game creation
The Shiptest Codebase
You can make it - Open Source MMORPG Platform
Widelands is a free, open source real-time strategy game
A game of dungeon exploration, combat and magic
Build multiplayer web games played by millions
Sandbox video game with a powerful physics engine
Free and open source real-time strategy game
The Ren'Py Visual Novel Engine
Multi Theft Auto is a game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF