A development environment focused on modding
An easy to use tool to change the behaviour of your input devices
A retro game engine for Python
Lutris desktop client in Python
Open source clone of the Age of Empires II engine
Tool made to launch the popular Game Trainer / Cheat tool
Powerful, mature open-source cross-platform game engine for Python
Free, open source game engine online
RPG Maker 2000/2003 and EasyRPG games interpreter
Doom-based AI research platform for reinforcement learning
The Pokémon API
3D game engine/framework in C, with Luajit and Python bindings now
A terminal based Pokemon like game
CTFs as you need them
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
StarCraft II learning environment
Pycraft is an open-source, OpenGL based game made in Python
GemRB is a portable open-source implementation of the Infinity Engine
Cooperative multiplayer graphical RPG and adventure game
For exploring cellular automata like Conway's Game of Life.
4X Space Strategy Game
Unofficial classic styled Minecraft Launcher
3D modeler, 3D game maker, 3D demo maker