Open Source Games

GitHub repository ↗ synced 2026/8/9

Awesome Open Source Games

Open source games that have the source code available.

Major Companies

A selection of major game studios, publishers, etc. using GitHub:

Browser-Based

Boardgame

3D Hartwing Chess Set

3D chess game done in HTML/CSS/JavaScript.

Connect Four game where player is playing against an AI.

Desperate Gods

Free online board game that was designed to be played just like a board game in real-life: no rules are enforced by the computer.

Duet (Veiled Dominion)

Open-source asymmetric chess variant with an inverted win condition — the game ends when your transformed piece loses control, not when your immobile king is threatened. Includes an AI opponent, remote multiplayer, and an optional fog-of-war mode.

Green Mahjong

Solitaire mahjong game done in HTML/CSS/JavaScript.

Kriegspiel

The game of imperfect information, the Kriegspiel chess variant.

Chessmata

Open-source multiplayer chess platform for humans and AI agents, with real-time WebSocket gameplay, Elo-based matchmaking, 3D browser board (Three.js), MCP server, and UCI-compatible CLI. Built with Go and React.

Lichess

Free chess game using HTML5 & websockets built with Scala, Play 2.8, MongoDB and Elasticsearch.

Wolfcha

AI-powered Werewolf (Mafia) social deduction game where every player is controlled by top LLMs. Built with Next.js and TypeScript.

Arcade

Alge's Escapade

Help Alge escape by moving through the levels to the escape tube.

Alien Invasion

Don't let the aliens reach the bottom, eliminate them using your spaceship.

Arashi

Clone of the Arcade game Tempest. Survive as long as possible and score many points as possible.

Asteroids

Pure JavaScript asteroids. Destroy asteroids ans saucers controlling a triangular ship rotating left and right.

Avabranch

Get your Ava away from the blocks moving between them.

Ball And Wall

Destroy the blocks using the Vaus, that is ejected from the ship.

Breakout

Multiplayer with HTML5. Destroy the blocks using one ball from your ship.

Captain Rogers

HTML5 mobile game created using ImpactJavaScript.

Ceros Snake

A remake of the iconic 70's Snake game.

CHANG€

Intense game about the extreme life of supermarket cashiers.

Chromacore

2D musical platformer set in a dark, black & white world that progressively becomes more colorful and happy through successful gameplay.

Jolly Jumper

Infinite jumping style game inspired by Doodle jump.

Clumsy Bird

Flappy Bird clone in JavaScript using MelonJavaScript.

Coffee Snake

HTML5 snake game written in CoffeeScript.

Coil

HTML5 canvas game where you defeat enemies by wrapping enemies in your trail.

Color Quest

Infinite runner following a black and white pixel's quest to change into a color pixel.

Core Commiter

Choose an open source project and help that project by sorting code to proper branches.

Crappy Bird

Flappy Bird clone in JavaScript and Canvas2D API.

Custom Tetris

Play the classic Tetris game the way you like it.

D3shooter

Asteroids style game in HTML5 as a demo of the d3 library.

Digger

The player is placed in an underground maze and can dig horizontal and vertical tunnels through it.

Drakonas

Classic shoot 'em up game build with the Three.js library.

Drill Bunny

Drill game with a bunny finding good stuff under the earth.

DuckHunt JavaScript

DuckHunt ported to JavaScript and HTML5 with a level creator.

Emberwind

Fantasy game port of the indie platform game Emberwind.

ExecutiveMan

Clone of NES game MegaMan, written in JavaScript.

Fluid Table Tennis

Renders a table tennis game interacting with a full-color real-time fluid simulation at 60 FPS.

Heal 'em All

Explore old, abandoned graveyard, heal as many zombies as you can, and find your way out. But be careful not to become one of them.

HotFix

Help Hotfix collect stargazers and avoid enemies. Collect commits to upgrade hotfix and add new features.

Hyperspace Garbage Collector

Guide N4n through the dangerous trash-heap caverns to reach the Primary Systems Core and restore compliance to the Trash.

I Spy A Ghost

An experimental p2p multiplayer game made in HTML5/Phaser using WebRTC.

Jekyll & Hyde Collide

Simple Unity 2d game that is very literally based around the theme of "change" using the classic Jeykll and Hyde story.

JumpSuit

With your awesome suit, jump from planet to planet to conquer them.

Mario 5 HTML

Infinite Mario in HTML5 JavaScript using Canvas and Audio elements.

Mega Girl

The hyper-deluxed-super-mega software that beats back those malicious apps.

Masonry JavaScript Tetris Clone

Tetris clone created using HTML5/JavaScript/Phaser.

Monster Wants Candy

Simple HTML5 game created with Phaser 2.0.7.

Octocat Jump

Navigate your ever-jumping Octocat and collect stars for extra points.

Onslaught Arena

Fight off hordes of classic medieval monsters in this fast paced arcade shooter.

Pappu Pakia

Addictive game where you guide little Pappu around obstacles while collecting coins, stars, and berries and avoiding enemies known as Pakias.

Phaser Snake

JavaScript version of the snake game, created using the Phaser Engine.

PixelPlatformer

Simple platformer game that demostrates the power of the Entity game engine.

PolyBranch

Minimalist 3D game. Dodging branches may seem easy at first, let's see how long can you hold up as you approach terminal velocity.

Protocol 390

To survive in People's Park, you must supply the prophet with change.

Raging Gardens

JavaScript/HTML5 web browser game where a a hungry (ninja) rabbit farts too often.

Release Cycles

Abstract racing game where you fight against the clock and the computer to get as far as you can in a product's life-cycle.

Save The Forest

Fully canvas based HTML5 game where a player has to extinguish fire on tress using his magical water tank in order to save the Burning Forests.

SKALP

60-second trading-floor reflex game. Go long or short, ride the chart, close before it reverses — and don't get liquidated.

Ski Free

Controls a skier on a mountain slope, avoiding obstacles while racing against time or performing stunts for points, depending on the game mode.

Snake

Simple clone of the snake game, using canvas and JavaScript.

Snake_new

Classic nokia snake game using web.

Space-Shooter

Classic shoot'em up space shooter build in HTML5 with multiplayer.

Spashal

Danger lurks around every corner in space.

Square Off!

Multiplayer 1v1 air-hockey style game, place squares to deflect the ball.

Space Crusade

HTML5 game developped with PhaserJavaScript Framework.

Super Mario Bros

One level written with Backbone Game Engine.

Survivor

Playable HTML + CSS + JavaScript remake of a space-based "shoot-'em-up" arcade game for Atari / Commodore 64 from 1982, including a level editor and design tool.

WPilot

Browser-based remake of the famous XPilot game, built with Node.js and HTML5.

Zedinvaders

Game is based on our original comic ZED, seen inside "zero-episode" called "Game Over".

111 one-button games

One button games are famous for realizing various actions with one button.

Rhythm

Bemuse

Online rhythm game playing songs in [BMS](https://github.com/wcko87/beatoraja-english-guide/wiki/BMS-Overview) format.

FPS

Backdooms

Game inspired by DOOM 1993 and The Backrooms, small enough to be self contained inside a QR code.

BananaBread

Port of the Cube 2/Sauerbraten 3D game engine/first person shooter to the web, compiling C++ and OpenGL to JavaScript and WebGL using Emscripten.

Nazi Zombies Portable

Call of Duty: Zombies "de-make" powered by various enhanced forks of the Quake engine.

RPG

Diablo JavaScript

Isometric minimal-code style game at HTML5 canvas and JavaScript.

Roguish

RPG/Rogue-like game created in JavaScript.

Room for Change

Randomly generated action RPG. You play as a chubby archeologist who is tasked to retrieve three sacred artifacts from the pyramid of the legendary Pharaohs.

MMORPG

BrowserQuest

HTML5/JavaScript multiplayer game experiment.

Reia

RPG game action-adventure MMO focusing heavily on story, combat, and an open-world sandox adventure. Built with Godot, Rust, and Zig.

Strategy

Ancient Beast

Materialize and control beasts in order to defeat your opponents.

Command & Conquer

Recreation of the original Command and Conquer, Real Time Strategy game entirely in HTML5 and JavaScript.

Freeciv-web

Build cities, collect resources, organize your government, and build an army, with the ultimate goal of creating the best civilization.

Hexa Battle

Turn based dungeon crawler written with TypeScript, using React and SVG.

Rapid Dominance

Open source turn-based strategy game. Clone of the Enemy Flag.

Tower Defense

3D Tower Defense build with Three.js in HTML5.

Racing

HexGL

Futuristic HTML5 racing game, challenge your friends on this fast-paced 3D game.

Trigger Rally Online Edition

Fast arcade rally racing action, play in your browser with WebGL 3D graphics.

Sandbox

3d.city

Goal was to build a city in 3D to test the performance of WebGL and and Three.js.

Blk Game

Fully modifiable multiplayer voxel world in JS that can run efficiently in the browser.

Cube Engine

Resembles that of Minecraft, a popular voxel-type 3D game based on boxes.

Sandboxels

Falling-sand experimentation game with over 500 materials to play with.

Puzzle

2048

Clone of 1024, based on Saming's 2048.

A Dark Room

Dodge and shoot the red targets, grabbing the bombs as you go. Survive as long as possible and try to get a high score.

Anagramica

A word game and API for anagrams.

Astry

WebGL maze game built with Three.js and Box2dWeb.

Beatrix

Music game where you arrange the drums to catch the beats and play the right rhythm.

BitBot

HTML/JavaScript game where you control a bot, which must sense, plan, and act.

BlicblockJavaScript

JavaScript game based on Blicblock in The Sims 4. Match tetrominoes to clear the board.

Blockrain.js

Embed & play the classic game on your site. Simple as that.

Branching Out

Minimalist game about leaving home.

Clone Man

Puzzle, memory, retro game with simple graphics.

Couch 2048

A physics-based puzzle, loosely related to the original 2048 game.

cube-composer

A puzzle game inspired by functional programming.

Drunken Viking

Retrace your drunken rampage in reverse time.

Ending

Roguelike puzzle game.

Follow me! A Simon Clone

Fully commented version of the famous game in JavaScript, built using Phaser game engine.

For King

Puzzle platformer game about a king in search for his lost crown.

Genetic Drift

Victor, an annoyed janitor dealing with a lot of annoyed clones and the problems that inevitably arise from genetic duplication. Will he make it home to feed his faithful pet companion?.

Hex 2048

Hexgrid-based clone of 2048.

Hexahedral

Push down all the blocks in the minimum number of moves.

Hextris

Addictive puzzle game inspired by Tetris.

Infectors

Sokoban-like puzzle game developed with Phaser.

Lost! Beneath the Surface

You're a firefly lost in the dark, beneath the surface and must find a way out of the mazes created by the horrors in the dark.

Monkey Rally

JavaScript game created for the Ludum Dare #28 jam.

Orbium

Modern version of the 90's game Logical.

Parity

A numbers puzzle game.

Pond

The Pound is about relaxing and exploring a beautiful world.

Pop Pop Win

Implementation of Minesweeper in Dart.

Prism

Match all the colors.

Push and Fork

Puzzle game in which you carry a fork, push blocks, and go back in time.

Shape Experiment

The shape recognition reflex game.

Sliding Puzzle

Sliding blocks puzzle game.

Sudoku JavaScript

A Sudoku puzzle game with a clean design and mobile devices in mind.

Swap

New take on the classic tile-based puzzle game, where you change which character you're controlling to reach your goal.

TransCube

2d puzzle platformer based on the concept of transforming into different "blocks", with their unique properties, and making you way to the end of the level with the provided transformations.

Untrusted

Meta-JavaScript adventure game by Alex Nisnevich and Greg Shuflin.

Matching Pairs

Made in HTML5 using Phaser as the framework, original assets and generated music.

Zoko

3D version of Sokoban.

Zop

Connect like colors.

Clicker

Particle Clicker

Addictive incremental game that teaches players the history of high energy particle physics.

Point and Click

The House

You're in a strange house. Can you find the way out? Is there any?

Others

Beast

An homage to the 1984 ASCII game "BEAST" from Dan Baker, Alan Brown, Mark Hamilton and Derrick Shadel written in node. You have to squash little ASCII beasts between pushable blocks but watch you to not be eaten by them.

Binb

Competitive, multiplayer, realtime, guess the song game.

CyberPong

Unusual Ping Pong game, adaptable with Makey Makey Kit.

Dental Defender: Saga of the Candy Horde

HTML5 shooter/tower defense game for the #CandyJam.

Descensus 2

A TypeScript 2D physics game.

Hauberk

ASCII-art based procedurally-generated dungeon crawl game. It's written in Dart and runs in your browser.

HeartLine

Game made in 48 hours for the 2013 Global Game Jam.

Project: Starfighter

Space shoot 'em up game.

Psiral

JavaScript/HTML5 game, GitHub Game Off 2 winner.

Squirts

Well-known indie game implemented in JavaScript.

The Killer

Flash/ActionScript3-based "nongame".

Turkey Cooking Simulator

You have been invited to craft the centerpiece of the American thanksgiving dinner, the turkey. Woo your girlfriend / boyfriend and be judged by your future in-laws! Apply your culinary expertise to impress your family.

Double Damnation

Exclusively Co-Op Metroidvania with Smash Bros Melee Movement.

Native

Action

Hypersomnia

Competitive top-down shooter with extreme dynamics and pixely nostalgia. Has a built-in map Editor.

OpenTomb

Open-source Tomb Raider 1-5 engine remake.

OpenLiberty

An open-source reimplementation of Grand Theft Auto III on the Godot Engine.

Arcade

C-Dogs SDL

Overhead shoot-em-up port of the classic DOS game.

Chaos Projectile

2D run'n'gun action game with RPG elements.

Clonepoint

Libre clone of Gunpoint, a game in which you hack and punch your way to victory.

DynaDungeons

Bomberman clone using the awesome open source Godot game engine.

Duckmarines

A ChuChu Rocket remake for PC.

Falling Time

Arcade game inspired by Fall Down.

Kroniax

Sidescrolling skill-based game.

Missile Command

Clone in Lua with LÖVE.

Mystic Mine

Single and multiplayer action game with mining carts.

OpenLieroX

Liero clone, like realtime Worms, or a 2D Quake.

OSGG

Oldskool Gravity Game, very difficult lander game in glorious vector graphics.

Savage Wheels

2D car crashing game similar to the old classic Destruction Derby.

Space Shooter

Cross platform, 2D space shooting game made using pygame.

SDL-Ball

Pretty looking breakout clone available in most distributions.

Taisei

Fan-made, open Source clone of the Touhou series.

Teeworlds

Online multi-player platform 2D shooter.

Wannabe Tempest

Tempest(80's arcade game) clone in Java, and a small project for playing with git.

Witch Blast

Roguelite dungeon crawl shooter similar to The Binding of Isaac.

Rhythm

osu!

Rhythm is just a *click* away!

Stepmania

Cross-platform dance rhythm game.

lr2oraja

[BMS player](https://github.com/wcko87/beatoraja-english-guide/wiki/BMS-Overview), fork of [beatoraja](https://mocha-repository.info/download.php) (popular BMS player) using Lunatic Rave 2 (LR2) gauges and judge (Requires a JVM. Recommended: [Liberica OpenJDK](https://bell-sw.com/pages/downloads/) Full version).

lr2oraja \~Endless Dream\~

BMS player, fork of lr2oraja with additional features (Requires a JVM. Recommended: [Liberica OpenJDK](https://bell-sw.com/pages/downloads/) Full version).

FPS

AssaultCube

Total conversion of Wouter van Oortmerssen's FPS called Cube.

Darkest Hour

World War 2 online multiplayer tactical shooter based on Red Orchestra: Ostfront.

Freedoom

Free software FPS based on the classic Doom engine.

GlPortal

A modern 3D game and engine with portals written in C++.

Ioquake3

The free software FPS engine that can be used to play Quake 3, or make your own game.

Nazi Zombies Portable

Call of Duty: Zombies "de-make" powered by various enhanced forks of the Quake engine.

OpenLara

Tomb Raider open-source engine.

Openspades

Compatible client of Ace of Spades 0.75.

Red Eclipse

Fun-filled new take on the first person arena shooter, featuring parkour, impulse boosts, and more.

Unvanquished

Fast-paced, futuristic FPS with RTS elements.

Urban Terror

Free multiplayer first person shooter that will run on any Quake III Arena compatible engine.

Warsow

Fast-paced FPS in a futuristic cartoonish world.

Xonotic

An addictive arena-style first person shooter with crisp movement and a wide array of weapons.

MMORPG

Open-Ko

Reimplementation of old-school Knight Online that replicates the 1299 client functionality while preserving accuracy and compatibility with the version 1299 client and server.

Meridian 59

The first 3D MMORPG, released in 1996 and open sourced in 2012 - the game is being actively developed by the community.

Reia

RPG game action-adventure MMO focusing heavily on story, combat, and an open-world sandox adventure. Built with Godot, Rust, and Zig.

Stendhal

Fun friendly and free 2D multiplayer online adventure game with an old school feel.

Veloren

An action-adventure role-playing game set in a vast fantasy world.

RPG

Angband

Single-player dungeon exploration game in the universe of JRR Tolkien.

Arx Fatalis

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

Cataclysm: Dark Days Ahead

Roguelike set in a post-apocalyptic world.

Cendric

Platformer-RPG in a fantasy setting with puzzle elements.

Dungeon Crawl Stone Soup

Single-player roguelike dungeon exploration game with a larger focus on combat compared to other popular roguelikes.

Dungeon Monkey Eternal

Party-based fantasy roguelike role-playing game.

Egoboo

Cool 3D dungeon crawling game in the spirit of NetHack.

Flare RPG

Fantasy action RPG game with its own engine.

Freeablo

Open-source implementation of the Diablo I engine.

NetHack

Single-player roguelike dungeon exploration game and one of the most popular games in its genre.

OpenMW

Reimplementation of the Morrowind game engine.

Shattered Pixel Dungeon

An open source game based on the source code of Pixel Dungeon by Watabou.

The Legend of Zelda: Mystery of Solarus DX

Sequel to The Legend of Zelda: A Link to the Past released on the SNES.

Valyria Tear

Single-player medieval-fantasy 2D J-RPG.

Legend of Elya

World's first LLM on Nintendo 64. 819K-parameter nano-GPT transformer running live inference on MIPS R4300i at 60 tok/s. Zelda-style dungeon crawler with AI NPCs. Built with libdragon SDK.

Platform

AAAAXY

Nonlinear 2D puzzle platformer taking place in impossible spaces.

Commander Genius

Commander Keen compatible clone.

DDraceNetwork

Cooperative online precision platformer with thousands of maps and global ranks.

Elemental One

Built with the Phaser HTML5 game framework.

Escape of the cat

Hardcore oldschool platformer on [INSTEAD](http://github.com/instead-hub/instead).

Frogatto

Action-adventure game, starring a certain quixotic frog.

Gish

Award-winning physics platformer.

Journey to the Center of Hawkthorne

This 2d platformer is based on Community's Digital Estate Planning episodebuilt using the LÖVE game engine.

Mario-Level-1

First level of Super Mario Bros made with Python and Pygame.

HFT Mario Party

A remixed local multiplayer reimagining of the original Mario Bros.

Sky Engine

Custom engine 2D platform game made with OpenGL.

The Legend of Edgar

2D platform game with a persistent world.

The Secret Chronicles of Dr. M.

A 2D platform game in classic style.

ReTux

Platformer game inspired by SuperTux.

Super Bombinhas

Retro platformer game.

SuperTux

Classic 2D jump'n'run sidescroller with Tux.

Puzzle/card/board

2048-cli

CLI version of the game 2048 for your Linux terminal.

2048-in-terminal

CLI version of the game 2048 made right.

Castles of Dr. Creep

The Castles of Dr. Creep.

Dominion

C# implementation of Dominion, a board/card game.

EbbeFlut

Really nice board game implemented in a bad way a VERY long time ago.

IRMINGARD

Patience card game written in Ruby.

Minilens

Cute puzzle platformer starring a cleaning robot on post-apocalyptic Earth.

Nudoku

Ncurses based CLI sudoku game.

PuzzleDash

Match-3 puzzle game.

Tictactoe

Graphical tic-tac-toe AI which never loses.

Wizznic

Most awesome puzzle game.

PokerTH

Implementation of Texas Hold'em supporting (online) multiplayer and botplay.

Racing

Stunt Rally

Rally game with Track Editor, based on VDrift and OGRE.

SuperTuxKart

Free 3D kart racing game featuring open source mascots.

Programming

CengBall

Soccer programming game with 2D simulation.

Sandbox

Blackvoxel

Sandbox game based on a molecular voxel interaction engine.

Blocks Beyond the Stars

Block-based 3D space crafting sandbox with procedurally generated planets, block-by-block ship & base building and self-hostable multiplayer (Unity client, .NET server).

Craft

Simple Minecraft clone written in C using modern OpenGL.

Endless Sky

Space trading and combat game similar to the classic Escape Velocity series.

Freeminer

Sandbox game inspired by Minecraft.

Minecraft

Simple Minecraft-inspired demo written in [Python](https://www.python.org/) and [Pyglet](http://www.pyglet.org/).

Manic Digger

A multiplayer block-building voxel game, Minecraft clone.

Minetest

Infinite-world block sandbox game with survival and crafting.

Pycraft

A Minecraft-inspired game for the terminal.

Rigs of Rods

Soft-Body physics simulator for vehicles and more.

Space Engineers

Voxel-based sandbox game set in an asteroid field in space.

Starbound

A 2D sandbox adventure game where players explore a vast procedurally generated universe.

Terasology

Voxel world game engine inspired by Minecraft and others with fancy graphic effects and a heavy focus on extensibility.

The Powder Toy

Falling-sand physics sandbox game.

Unturned

Free open-world zombie survival sandbox game.

Simulation

Hurry Curry!

Cooperative fast-paced multiplayer cooking game.

Strategy

0 A.D.

3D RTS similar to Age of Empires II.

Beyond all Reason (BAR)

RTS born from mods of the Total Annihilation on the SpringRTS game engine.

Caesaria

Remake of the popular citybuilder and economic sim Caesar III.

Colobot

A real-time strategy game with programmable bots.

CorsixTH

Clone of Theme Hospital.

Curse of War

Fast-paced action strategy game with ncurses and SDL frontends.

Harris

Strategy game based around the actions of RAF Bomber Command in the Second World War.

Hedgewars

A turn based strategy, artillery, action and comedy game.

KaM Remake

RTS game remake of “Knights and Merchants” written in Delphi from scratch.

KeeperRL

Roguelike dungeon builder inspired by Dwarf Fortress.

Last Colony

RTS game with both a single player campaign mode as well as a multiplayer mode, created entirely in HTML5 and JavaScript.

MegaGlest

Real-time strategy game engine (cross-platform, 3-d).

Micropolis

City-building game based on the original code for SimCity.

Mindustry

An open source sandbox tower-defense game.

Openage

Clone of the Age of Empires II engine.

OpenDungeons

Open source game inspired by Dungeon Keeper - Dark, damp and dangerous.

OpenE2140

Remake of Earth 2140 based on [the OpenRA engine](https://github.com/OpenRA/OpenRA)

OpenFodder

Open-source implementation of Cannon Fodder.

OpenKrush

Remake of KKnD (Krush, Kill 'n' Destroy) and KKnD2 based on [the OpenRA engine](https://github.com/OpenRA/OpenRA)

OpenRA

Open-source implementation of the Red Alert engine using .NET/mono and OpenGL. Runs on Windows, Linux and macOS.

OpenSA

Remake of Swarm Assault based on [the OpenRA engine](https://github.com/OpenRA/OpenRA)

OpenTTD

Transport simulation game based upon the popular game Transport Tycoon Deluxe, written by Chris Sawyer.

OpenXcom

Clone of the original X-COM.

Pax Britannica

Underwater one-button real-time strategy game.

PCOTM (Phone Case of the Monster)

Ruby game, where you play as a phone-collecting monster.

Pikifen

Fan-made Pikmin-based engine, built with flexibility in mind.

Pioneer

Game of lonely space adventure.

Polly-B-Gone

Physics platform game about a plucky wheeled robot named Polly.

OpenRCT2

Open source recreation of Rollercoaster Tycoon 2.

Race into Space

Turn-based space race strategy game originally by Interplay.

Romanov's Vengeance

Remake of C&C Red Alert 2 based on [the OpenRA engine](https://github.com/OpenRA/OpenRA)

Seven Kingdoms: Ancient Adversaries

Classic RTS game liberated in 2009.

Shattered Paradise

Remake of C&C Tiberian Sun based on [the OpenRA engine](https://github.com/OpenRA/OpenRA)

Source of Tales

Entry in the Liberated Pixel Cup 2012.

Tanks of Freedom

Turn-based strategy game in isometric pixel-art style.

The Battle for Wesnoth

Turn-based strategy game with a high fantasy theme.

Unknown Horizons

2D isometric RTS economic strategy game written in C++ & Python, built on the Flexible Isometric Free Engine.

Voxeliq

Block-based game engine implementation developed with C#.

Wargus

Warcraft2 Mod that allows you to play Warcraft2 with the Stratagus engine.

Warzone 2100

Postnuclear realtime strategy.

Wyrmsun

Strategy game based on history, mythology and fiction.

Zero-K

Open source RTS game with physical projectiles and smart units.

Stone Kingdoms

Real-time strategy based on the original Stronghold series.

Mobile Games

Android

Braincup

Memory, focus & math trainer.

ChaseWhisplyProject

Chase Whisply is a FPS. You have to seek, find and kill the ghosts living around you.

Colorphun

Simple color based Android Game.

Game of Life

Conway's Game of Life with editable rules.

Gidi Games

Lexis, TicTacToe, Puzzlemania - a collection of 3 board games done with Cocos2d for Android.

Green Wall

Weirdly addictive arcade-style Android game, where you fling fruit at a wall. Project developed using Android Studio 1.0.

Memory Game

Simple and beautiful memory game for kids.

Pimple Popper

Game to pop pimples using the awesome Godot Engine.

Pixel Dungeon

Traditional roguelike game with pixel-art graphics and simple interface.

PuzzleGame

Slider puzzle game implementation created with Cocos2d for Android.

Wannabe Tempest

Clone of 80's coin-op arcade game Tempest(80's arcade game).

ZapZap

Very simple reaction measuring game that can also be played together on the same device.

iOS

Bat Loves Bugs

Arcade game about a bug-craving bat.

Bridges

Puzzle game with bridges, houses, tolls, and subways for iOS.

Canabalt

Release of Canabalt for iOS.

Choose Figure

Simple logic game. Choose the right figure. Train your attention.

Doom

Classic Doom Game for iOS.

DrugsNRock

Simple multiplayer rhythm game designed during the 2013 Global Game Jam.

FinalFighter

Tank deathmatch battle game developed using Cocos2D.

Gorillas

Iphone port of the popular old QBasic game.

Light Jockey

iOS Auditorium-like game.

Lumio

Puzzle game for iOS developed using Cocos2D. Available free on the App Store.

Sakura Fly

iOS action game developed using SpriteKit. Available free on the App Store.

Wolfenstein 3D

iOS Source Release.

Chat bots

c4bot

Chat bot that plays Connect Four with you, works in web chat, Facebook Messenger, Skype, and Telegram.

Just The Source

Aquaria

Breath-taking underwater fantasy game. Winner of the Grand Prize at the 2007 Independent Games Festival.

Descent 3

Pilot a fighter in a six-degree-of-freedom shooter across underground and surface environments.

Doom 3

GPL source code release.

ID Software

Includes Doom, Quake, Wolfenstein and more.

Jedi Academy

Source only, mirror of SourceForge from Raven Software.

Jedi Outcast

Source only, mirror of SourceForge from Raven Software.

MaNGOS

Full featured World of Warcraft server.

Miner Wars 2081

For modders of Miner Wars 2081, a 6DOF action-survival space-shooter simulation-game set in the year 2081.

OpenJK

Community maintained fork of Jedi Academy and Jedi Outcast development.

Prince of Persia

Source code for the original Prince of Persia game that was written on the Apple II, in 6502 assembly language, between 1985-89.

UFO RUN

Real time multiplayer with Nextpeer.

System Shock

Source code for original System Shock game (PowerMac version), more readable fork available [here](https://github.com/ToxicFrog/shockmac).

Rogue Legacy

Source code for Rogue Legacy 1.

Frameworks/Engines/Libraries

Unreal Engine

C++ AAA game engine. It isn't completely free, but you can easily get access to the full source code. https://www.unrealengine.com/

Akihabara

Set of libraries, tools and presets to create pixelated indie-style 8/16-bit era games in JavaScript.

Allegro 5

C++ libraries to make 2D games(graphics, sound, etc.).

Ammo.js

Direct port of the Bullet Physics engine to JavaScript using Emscripten.

Atomic Engine

Features 2D and 3D rendering, standards compliant JavaScript, full Player and Editor source on GitHub, Windows & Mac Editors, with deployment to Windows, Mac, WebGL, Android, and iOS from the editor.

Babylon.js

Complete JavaScript framework for building 3D games with HTML 5 and WebGL.

Bgfx

Cross-platform rendering library.

Chilli Works

An open source, cross-platform game engine designed for indie developers.

Chipmunk Physics

Simple, lightweight, fast and portable 2D rigid body physics library written in C.

ChoiceScript

A language/engine for developing text-based multiple-choice interactive novels.

Cocos2d for Android

Based on cocos2d-Android-0.82, and now ported from cocos2d-iphone 0.99.4.

Cocos2d for iPhone

Framework for building 2D games, demos, and other graphical/interactive applications for iPod Touch, iPhone, iPad and Mac. It is based on the cocos2d design but instead of using python it, uses objective-C.

Cocos2d for HTML5

Cocos2d for Web Browsers. Built using JavaScript.

Cocos2d-x

Multi-platform framework for building 2d games, interactive books, demos and other graphical applications. It is based on cocos2d-iphone, but instead of using Objective-C, it uses C++. It works on iOS, Android, Windows Phone, macOS, Windows and Linux.

Crafty

JavaScript game library that can help you create games in a structured way.

CutJavaScript

Lightweight and fast 2D HTML5 rendering engine for cross-platform game development.

Dash

Free and open 3D game engine written in D.

Duality

2D Game Development Framework.

EaselJavaScript

Library to make working with the Canvas element easier.

EntityJavaScript

HTML5 JavaScript game engine utlizing the entity-component design.

Evennia MUD/MU* Creation System

Library for creating online multiplayer text games (MUD, MUSH, MUX, MUCK, MOO etc) in pure Python.

Flare

Free/Libre Action Roleplaying Engine.

Flashpunk

Free ActionScript 3 library designed for developing 2D Flash games.

Flixel

Game-making library written entirely in ActionScript 3.

GameJavaScript

GameJs is a JavaScript library for writing 2D games or other interactive graphic applications for the HTML Canvas inspired by PyGame.

GamePlay

Cross-platform, C++ game framework/engine for creating 2D/3D mobile and desktop games.

GemRB

Cross-platform implementation of Bioware's Infinity Engine.

GenesisEngine

Allows you to create and explore procedurally-generated planetary systems, from ground level all the way out into space. Experiments with procedurally-generated worlds, XNA, and design patterns.

Gladiator 3D

Canvas based JavaScript ray casting engine for pseudo 3D games.

Godot

Fully featured, MIT licensed, game engine. It focuses on having great tools, and a visual oriented workflow that can export to PC, Mobile and Web platforms with no hassle. The editor, language and APIs are feature rich, yet simple to learn, allowing you to become productive in a matter of hours.

HaxeFlixel

Free, cross-platform 2D game engine powered by Haxe and OpenFL.

Ikemen GO

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

JiGS

Online RPG and Trading Game Engine built in PHP.

JMonkeyEngine

Cutting edge, cross-platform 3D game engine for adventurous Java developers.

Kiwi.js

Blazingly fast mobile & desktop browser based HTML5 game framework. It uses CocoonJavaScript for publishing to the AppStore.

LibGDX

Desktop/Android/HTML5/iOS Java game development framework.

LibRocket

C++ user interface package based on the HTML and CSS standards. It is designed as a complete solution for any project's interface needs.

LibSDL2pp

C++11 bindings for [SDL 2.0](http://libsdl.org/).

Matter.js

JavaScript 2D rigid body physics engine for the web.

MelonJavaScript

HTML5 game framework for 2D games.

MonoGame

XNA Implementation for Mono based platforms (supports iOS, Android, Linux, and started work on PS Suite and NaCli ).

Oimo.js

Lightweight 3d physics engine for JavaScript.

OpenRTS

Real-Time Strategy game 3D engine coded in java 7.

osu-framework

A game framework written with osu! in mind.

Oxygine

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

panda.js

Free HTML5 game engine for mobile and desktop with Canvas and WebGL rendering.

Phaser

Fun, free and fast 2D game framework for making HTML5 games for desktop and mobile web browsers, supporting Canvas and WebGL rendering.

PhysicsJavaScript

Modular, extendable, and easy-to-use physics engine for JavaScript.

pixi.js

Super fast HTML 5 2D rendering engine that uses WebGL with canvas fallback.

Plasma

Cyan Worlds's Plasma game engine.

PlayCanvas

3D WebGL game engine with online toolset.

QICI Engine

Free JavaScript game engine library with a web-based comprehensive suite of toolset for making HTML5 games.

Quasi-Engine

QtQuick framework that intends to be a complete toolset to ease 2d game development.

Ren'py

A Visual Novel Engine, written in python, for both mobile (iOS beta) and desktop platforms.

SFML

Simple and Fast Multimedia Library.

Solarus

An Action-RPG game engine written in C++.

Spring

Real Time Strategy game engine.

Starling

ActionScript 3 library that mimics the conventional Flash display tree architecture, can be deployed to mobile devices (iOS, Android), the desktop (Windows, macOS), and to the browser (via the Flash plugin).

Superpowers

TypeScript & ThreeJavaScript powered game engine and framework (2D & 3D with WebGL).

Tesseract

Make mapping more fun by using modern dynamic rendering techniques, sothat you can get instant feedback on lighting changes, not just geometry.

Three.js

JavaScript 3D library used in many browser games.

Tiled

General purpose tile map editor. It is meant to be used for editing maps of any tile-based game, be it an RPG, a platformer or a Breakout clone.

Torque 2D

MIT Licensed version of Torque 2D from GarageGames.

Torque 3D

MIT Licensed version of Torque 3D from GarageGames.

Turbulenz Engine

HTML5 game engine and server-side APIs available in JavaScript and TypeScript for building and distributing 2D and 3D games.

Urho3D

Free lightweight, cross-platform 2D and 3D game engine implemented in C++ and released under the MIT license. Greatly inspired by OGRE and Horde3D.

Wurfel Engine

An isometric game engine for games with an open world made of blocks or voxels.

XLE

Rendering engine with advanced features such as Image Based Lighting, dynamic area lights, and a node based material editor. Flexible and modular, it is designed to drop into existing solutions. XLE is the "hackable" engine, intended to be customised for specialised requirements.