Awesome Open Source Games

Unknown Horizons official code repository

Real-Time Strategy game 3D engine coded in pure java

An open-source fighting game engine that supports MUGEN resources.

Kiwi.js is a blazingly fast mobile & desktop browser based HTML5 game framework. It uses CocoonJS for publishing to the AppStore.

System Shock (PowerMac version / Official GPL Release)

BananaBread is a C++ 3D game engine that runs on the web using JavaScript+WebGL+HTML

An open-source Tomb Raider 1-5 engine remake

a 2D Game Development Framework

Freedoom is an entirely free software game based on the Doom engine.

Compatible client of Ace of Spades 0.75

Source code of open-source Colobot: Gold Edition project developed by Epsitec and TerranovaTeam

⬤▗▚▚▚ Web-based online rhythm action game. Based on HTML5 technologies, React, Redux and Pixi.js.

Main development repository for Rigs of Rods soft-body physics simulator

GemRB is a portable open-source implementation of Bioware’s Infinity Engine.

Indie Turn Based Strategy in Isometric Pixel Art

libRocket - The HTML/CSS User Interface library

Digital Estate Planning: The Game

flixel is a free Actionscript (Flash) library that I distilled from a variety of Flash games that I've worked on over the last couple years, including Gravity Hook, Fathom and Canabalt. It's primary function is to provide some useful base classes that you can extend to make your own game objects.

Unvanquished is a free and open source FPS/RTS hybrid game powered by the Daemon game engine. Historically based on Tremulous as a continuation with decades of work over it.

Automatically exported from code.google.com/p/micropolis

Cross-platform port of Arx Fatalis, a first-person role-playing game

Classic overhead run-and-gun game

AssaultCube

Flash + AIR sound effects generator. Based on Sfxr.

Isometric minimal-code style game at html5 canvas and javascript

Source code of KeeperRL

HTML5 Tetris Game for jQuery

RPG game action-adventure MMO built with Godot and Rust.

⚔️ A cross-platform, open source, and super fast MUD client with scripting in Lua

A free JavaScript game engine library with a web-based comprehensive suite of toolset for making HTML5 games. http://www.qiciengine.com

DOOM Classic for iOS Source Release

Open source RTS game running on the Spring/Recoil engine

DDraceNetwork, a free cooperative platformer game

Oxygine is C++ engine and framework for 2D games on iOS, Android, Windows, Linux and Mac

Command & Conquer in HTML5/Javascript

Call of Duty: Zombies demake, powered by various Quake sourceports. https://docs.nzp.gay/

Panda Engine - HTML5 Game Engine

Star Wars Jedi Knight: Jedi Academy

This repository was moved to GitLab: https://gitlab.com/solarus-games/solarus

Frogatto & Friends is an action-adventure game, starring a certain quixotic frog.

Stendhal is a fun friendly and free multiplayer online adventure game with an old school feel.

AI-powered Werewolf (Mafia) social deduction game where every player is controlled by top LLMs like DeepSeek, Qwen, Gemini, and more

An addictive incremental game that teaches players the history of high energy particle physics

NOTE: development in stuntrally3 repo. 3D racing game based on VDrift and OGRE with own Track Editor. The main repository with Stunt Rally 2.x sources and data.

PokerTH is a poker game written in C++/Qt.

A self-contained game that fits inside a QR code inspired by DOOM 1993 and The Backrooms

DuckHunt ported to JS and HTML5

A WebGL maze game built with Three.js and Box2dWeb.

Open Fodder: An open source port of Cannon Fodder

C++ bindings/wrapper for SDL2