Games on this list were included based on recommendations, if you'd like to a game added to this list, please post it on the sticky of /f/Games. For a more comprehensive list, please see this Wikipedia page.
- Ardentryst - Action/RPG sidescroller.
- Beneath a Steel Sky - Classic adventure game with excellent artwork and voice talent. Should be available in the Ubuntu repos
- Egoboo - Action-adventure rogue-lite game
- Eldevin - F2P Runescape clone with a distinct charm
- Epic Inventor - Side-scrolling, Action RPG inspired by Terraria.
- Flare - A surprisingly in-depth and polished isometric RPG
- FreedroidRPG - Diablo-style ARPG.
- Lugaru - Turner, is an anthropomorphic rebel bunny rabbit with impressive combat skills. In his quest to find those responsible for slaughtering his village.
- Myst Online: Uru Live - MMO adventure game in where players interact with others to solve puzzles and advance the story.
- ScummVM's Freeware Games - Some fantastic point'n'click games here, my favourite probably being Dreamweb
- Solarus Games - Solarus is a game engine for making Zelda-like games, but there are many completed games available on their website, and also community made games
- Summoning Wars - Action roleplaying game for singleplayer or up to 8 players in multiplayer.
- Altitude - 2D Online plane combat
- Chromium-BSU - Top-down arcade Shmup
- Deflector - Retro style, ball bouncing, arcade game.
- Kobo Deluxe - 8-way scrolling shooter
- LBreakoutHD - Open-source breakout clones.
- OpenTyrian - The famous Shmup
- SSVOpenHexagon - Open-source clone of Super Hexagon. Source code for packagers
- Super Tux Party - Party game that is meant to replicate the feel of games such as Mario Party. (Source code)
- TeeWorlds - Online 2D shooter
- Witch Blast - Open-source clone of Binding of Isaac. Source code here for packgers.
- Hummingbird - Infinite procedural musical exploration game.
- Passage - A simple experimental side scroller game intended as an abstract metaphor for the human condition.
- Apple Flinger - Angry Birds-clone for Android.
- Atomic Tanks - Multi-platform Scorched Earth clone similar to the Worms series.
- Cat-O-Pult - Castles/Worms type of a game, but in this one you use cats as your weapon of choice.
- Gusanos - Clone of the DOS game Liero.
- Argentum Age - Open-source fantasy card game
- c4 - Connect Four game, with AI. Source code
- Desperate Gods - Online board game where no rules are enforced by the computer, and all moves are performed in a shared physical space. The game itself is a dark fantasy dungeon crawl for up to four players.
- Domination - Game based on the board game "Risk".
- Lichess (source code), Lucas Chess, 3D Hartwing Chess Set (source code) and DroidFish Android Chess App - Chess games.
- Magarena - Single-player fantasy card game.
- OGS Mahjong, Green Mahjong (source code) - Games of Mahjong.
- PokerTH - Free online poker with the best open source texas holden poker game and a great community
- PySolFC, Solitaire.gg, Aisleriot - Collection of solitaire games.
- Quatter- Game of Quarto.
- RosettaStone - Hearthstone simulator using C++ with some reinforcement learning.
- Scrabble3D - Highly customizable Scrabble game. Supports Classic Scrabble, Superscrabble and also 3D games and own boards.
- CorsixTH - Clone of Theme Hospital
- Freeserf - Clone of The Settlers 1/Serf City.
- FreeTrain - Rail and business simulation inspired by the A-Train series of games.
- KeeperRL - Dungeon management and roguelike.
- LinCity-NG, Micropolis Web and 3d.city - Clones of SimCity.
- OpenSkyscraper - Clone of the simulation game SimTower.
- OpenTTD (GNU/Linux, Windows & Mac) - a transport simulation game based upon the popular game Transport Tycoon Deluxe, written by Chris Sawyer.
- OpenRCT2 (GNU/Linux, Windows & Mac) - An open source reverse engineering of Rollercoaster Tycoon 2. Requires assets from the original game, acquirable here
- Scorched 3D - Simple turn-based or real-time artillery strategy game
- Simutrans - Open-source transportation simulator clone.
- The Founder - Dystopian business-simulator. Source code
- Unknown Horizons - Village builder inspired by the Anno series
- Widelands - Polished Settlers clone
- OpenOMF - Remake of One Must Fall 2097.
- Alien Arena - Retro Sci-Fi Online FPS
- Army Men III
- AssaultCube Reloaded
- Cube 2 - Quake-like Arena online FPS with multiple game modes
- ET Legacy - Wolfenstein: Enemey Territory for modern systems
- Digital Paint: Paintball 2 and Digital Paint: Paintball 3 - Fast-paced first-person shooters.
- FreeCS - Reimplementation of Counter-Strike 1.5.
- Freedoom - The Freedoom project aims to create a complete free content game based on the Doom engine.
- Nexuiz - Multiplayer first-person shooter.
- OpenArena - Online arena FPS using the id tech engine
- OpenSpades - Clone of Ace of Spades 0.75, featuring fully destructible terrain and plenty of game modes (including the well-known Capture the Flag).
- Quetoo - Multiplayer first person shooter based on id Tech2.
- Red Eclipse (GNU/Linux, BSD, Windows & Mac) - a free online arena shooter with parkour.
- Termulous - Asymmetric team-based RTS/FPS Hybrid with aliens! (Source code)
- Übergame - Realism like, multi-purpose, multiplayer, casual, first-person-shooter game.
- Unvanquished - First-person strategy shooter, pitting technologically advanced human soldiers against hordes of highly adaptable aliens.
- Urban Terror - Fast paced online FPS reminiscent of Counter-Strike
- Warsow (GNU/Linux, Windows & Mac) - a fast-paced FPS in a futuristic cartoonish world.
- Xonotic (GNU/Linux, BSD, Windows & Mac) - a free online shooter, based on Quake.
- Birdsong - Game about a bird that is about to leave the nest.
- Meteorite - Lowres FPS, inspired by Metroid Prime.
- The Diasporic Crypt - Libre game inspired by Castlevania, where you play a vampire who moves around in a portable teleporting catacombs underground.
- Evol Online - 2D MMORPG. Source code
- ImperiumAO - Source code
- PlaneShift - 3D fantasy MMORPG.
- Ryzom A game where there are no classes to choose, nor force to choose a faction or guild.
- Stendhal - 2D MMORPG.
- The Mana World - 2D MMORPG. Source code
- Auto Rhythm - Rhythm game with auto generated note maps.
- Frets on Fire X - Highly customizable rhythm game supporting many modes of guitar, bass, drum, and vocal gameplay for up to four players.
- osu! (Source code) and McOsu - Based on the gameplay of a variety of popular commercial rhythm games.
- Performous - Karaoke, band games and dancing in the same package.
- StepMania - Advanced cross-platform rhythm game.
- Turnt Ninja - Fast-paced rhythm game that uses your own music.
- UltraStar Deluxe - Clone of SingStar.
- CaveExpress - 2D platformer with physics-based gameplay.
- Golems - 3D physics simulator.
- Gravity Box - Puzzle platformer where you have to use bullet's blast to push towards the finish points.
- Neverball - Puzzle game inspired by Super Monkey Ball.
- Nikki and the Robots - Physics platformer.
- OpenGOO - Clone of the physics based puzzle / construction game "World of Goo".
- Rigs of Rods - Vehicle simulator based on soft-body physics.
- Safety Blanket - Creepy blanket simulator.
- The Powder Toy - Physics sandbox game, which simulates air pressure and velocity, heat, gravity and a countless number of interactions between different substances.
- XMoto - 2D motocross platform game.
- 2048 (Browser) - a sliding addition game.
- Blockout2 - 3D Tetris
- Duck Marines - Open-source clone of Chu Chu Rocket. Source code here for distro packagers.
- FloboPuyo - Open-source clone of PuyoPuyo. Source-code for packagers
- Frozen Bubble - Open-source clone of Bubble Bobble.
- Not Tetris 2 - Tetris with physics
- Pingus - Lemmings clone.
- Portable Puzzle Collection - 39 old school puzzle games
- Extreme Tux Racer and Tux Rider - Android Edition- High speed arctic racing games based on Tux Racer.
- Marble Marcher - Ray-traced racing game on the surface of evolving fractals.
- Speed Dreams - Motorsport simulation and racing game.
- Stunt Rally - Racing game with rally style of driving.
- The Open Racing Car Simulator - Car racing simulation.
- Trigger Rally - Fast-paced single-player racing game.
- VDrift - Racing simulator.
- Yorg - 3d racing game in the style of MicroMachines.
- Speed Dreams - Realistic racing sim
- SuperTuxCart - Open-source clone of the Mario Cart games (Not suitable for low-end systems)
- Yorg - A top-down racer in the Micro Machine's style.
Roguelikes / Roguelites
- ADOM (Ancient Domains of Mystery) - Another great roguelike, with a huge world and many ways to play
- Brogue - Your goal is to travel to the 26th subterranean floor of the dungeon, retrieve the Amulet of Yendor and return with it to the surface.
- Cataclysm: Dark Days Ahead - Unique zombie survival rogue-like, very thrilling to play.
- DoomRL - DOOM, but roguelike!
- Dungeon Crawl Stone Soup - A roguelike adventure to find the mystifyingly fabulous Orb of Zot.
- Fame - Fantasy roguelike game with graphics tiles, inspired mainly by ADOM.
- Kobold Dungeon Tester - Mix of a roguelike and a multiple choice text-adventure
- NetHack - Does this need an introduction?
- Planetary Sanitations Inc. - Roguelike mech dungeon-crawler
- Roguebox Adventures - Neat little graphical rogue-like with a focus on survival and crafting. Source code here for packagers
- Tales of Maj'Eyal: Age of Ascendancy - Ultra polished graphical roguelike with the option to save your game
- The Endless Dungeons - 8-bit style random dungeon game
- UnReal World - Crazy in-depth survival roguelike based in iron age Finland
- Andor's Trail - Single-player quest-driven fantasy RPG.
- Angband (GNU/Linux, Windows, Mac & Android) - a single-player dungeon exploration game in the universe of JRR Tolkien.
- Cataclysm DDA - Cataclysm: Dark Days Ahead is a turn-based survival game set in a post-apocalyptic world
- Crossfire - Cooperative multiplayer graphical RPG and adventure game.
- Erebus - Classic point-n-click style RPG.
- GearHead - Mecha roguelike.
- Red Rogue - Sidescrolling platformer-roguelite with optional realtime movement.
- Shattered Pixel Dungeon (Android) - a traditional roguelike game with pixel-art graphics and simple interface.
- Star Ruler 2 - Explore, expand, exploit and exterminate your way to become the ruler of the Galaxy.
- Tuxemon - Clone of Pokémon.
- ativayeban and FallingTime - Clones of Fall Down.
- Bard's Lesson - Platform game in which you help a bard fox in his journey to become a maestro by mastering music notation.
- Commander Keen 4 - Classic Shareware DOS title ported to Linux
- Dolphin Island 2 - Open source action-adventure platformer
- Fox Dash - Side scrolling 2D platformer for Android. Source code
- Frogatto - Platformer with great music and graphics. Should be available in the Ubuntu repos for free
- GOAT - An arcade game about a drunken space goat!
- Hurrican - Inspired by the classic game Turrican. Mostly forgotten nowadays, so you may have to compile it from here
- JVGS - Minimalistic platform game.
- Mega Mario, SuperTux, ReTux, Secret Maryo and The Secret Chronicles of Dr. M. - Clones of Mario. SupertTux is currently in need of help if it's to stay alive
- Mr. Rescue - Play as a fireman rescuing people. Source code here for people who want to package it for their distro
- OpenClonk - Weird Online 2D Mining
- Parallel Universe - Minimalist Yin and Yang Platformer.
- RickyD and xrick - Clones of Rick Dangerous.
- Sienna - Fun little runner/platformer. Source code
- Sonic Robo Blast 2 - 3D fangame based on the Sonic the Hedgehog series with many mods.
- Spelunky Classic HD - Cave exploration / treasure-hunting game inspired by classic platform games and roguelikes
- Super Mario War - A Super Mario multiplayer game in where the goal is to stomp as many other Marios as possible. (Switch port)
- Super Methane Brothers, The Bub's Brothers - Clones of Bubble Bobble.
- The Legend of Edgar - Action platformer game.
- Tobu Tobu Girl - Arcade platformer where you have to save your cat who is floating into the atmosphere.
- Robocode - Programming game, where the goal is to develop a robot battle tank to battle against other tanks in Java or .NET.
- 1010! Klooni - Minimalistic puzzle game.
- Bombman - Atomic Bomberman clone.
- Atomiks - Atomix clone.
- Crack Attack!, FreeBlocks and Panel Attack - Clones of the puzzle game Tetris Attack.
- Cuyo - Tetris-style puzzle game for up to two players.
- Gweled and Freegemas - Clones of Bejeweled.
- Hextris - Puzzle game inspired by Tetris.
- Lix and Rabbit Escape - Clones of Lemmings.
- Mice Men: Remix - Remake of the DOS game Mice Men.
- Mirror Magic - Arcade style puzzle game.
- OpenBlok - Clone of Tetris.
- Orbium - Clone of Log!cal.
- pocico - Puzzle game where the goal is to match the outer color with the inner color in every shape.
- Rocks'n'diamonds - Clone of Boulder Dash.
- Sudoku JS, Open Sudoku and Nudoku - Games of Sudoku
- Tanglet - Single player word-finding game based on Boggle.
- The Butterfly Effect - Clone of Crazy Machines.
- The lost Penguin - Guide laser beams through multiple mirrors to resolve the puzzles.
- Wizznic! - A difficult puzzle game with built-in puzzle-editor.
- GlPortal - Clone of Portal.
- Mari0 - Odd mix of Mario and Portal.
- Nova the Squirrel - NES game with ability copying and puzzles.
- Gnomescroll, ClassiCube and Freeminer - Minecraft-clones.
- Manic Digger
- Minetest - (GNU/Linux, FreeBSD, Windows, Mac & Android) - Uses C++, Requires mods to be fun
- OpenSpades - Clone of the team-based first-person shooter and voxel-based sandbox Ace of Spades.
- Terasology - Fancy lookin' Minecraft
- TrueCraft - Clean-room implementation of Minecraft 1.7.3
- Voxelands - Minecraft standard clone?
- voxel.js - Tool for creating minecraft clones
- Art Treachery - Stealthy art heist game.
- The Dark Mod - Fan-made spin-off the the fantastic Thief series (Not suitable for low-end systems)
Shoot 'em up
- Bloodworks - Top-down survival action game where you fight against an endless waves of monsters.
- C-Dogs SDL - Clone of the shoot 'em up C-Dogs.
- Chromium B.S.U. - Fast paced, arcade-style, top-scrolling space shooter.
- Dave Gnukem - Retro-style 2D scrolling platform shooter, inspired by and similar to Duke Nukem 1.
- Friking Shark - Remake of the shoot 'em up game Flying Shark.
- Gang Garrison 2 - Multiplayer 'demake' of Team Fortress 2.
- Galaxy Forces V2 - 2D multiplayer space shooter, inspired by the Amiga classic Gravity Force.
- heXon - Twin-stick-shooter for up to four players
- Lisparuga - 2D shoot-em-up game inspired by Ikaruga. (GNU/Linux systems only)
- M.A.R.S. - 2D space shooter.
- Maelstrom - Clone of Asteroids
- NightHawk - Clone of Paradroid.
- Relic Hunters Zero - Online cooperative shooter/RPG. Source code
- Torrega Race - Simple space game inspired by Omega Race.
- Violetland - Cross-platform game similar to Crimsonland.
- Watch out for Snakes - Short low poly top down retro arcade shooter.
- Witch Blast - Roguelite dungeon crawl shooter heavily inspired from Binding Of Isaac.
- Cart Life - Simulation game in which the player controls one of three street vendors, and attempts to run their shop whilst looking after their health, interests, and families. Source code
- Coming Out Simulator 2014 - Interactive game intended to help LGBT youth to understand their sexuality.
- Our Personal Space - Marriage survival sim set on a space colony in the near future.
- Two Interviewees - Short visual novel about the gender gap.
- Antares - Tactical space-combat game, combining elements of both arcade shooters and real-time strategy games.
- Bridge Command - An interactive ship simulator.
- EmptyEpsilon - A spaceship bridge simulator game
- Endless Sky - 2D space trading and combat game similar to the classic Escape Velocity series
- Naev - open-source game about space exploration, trade and combat
- Oolite - Well done Elite remake, with plentiful mod support.
- Pioneer - a remake of the sequel to Elite, Frontier.
- The Pandoran War - 2D mission-based space shooter.
- Ur-Quan Masters - Updated version of Star Control II. Be sure to download the Voice Pack! (Alternative HD version available here)
- Vega Strike - Open Source 3D Action-Space-Sim
- Bygfoot - Football/soccer management game.
- Classic 8-Ball Pool - Pool game written in JS and HTML5.
- FooBillard - OpenGL-based billiards simulation game.
- Goal Rush - Fast paced arcade game where two-robots team will face each other to score the maximum of goals during short matchs.
- YSoccer - Retro style, multi-platform soccer game.
- 0 A.D. (GNU/Linux, Windows, Mac) - a game of ancient warfare.
- Advanced Strategic Command and Crimson Fields - Clones of the turn based strategy game Battle Isle.
- Ancient Beast - A turn based strategy game similar to Heroes of Might and Magic.
- Anuto - Tower defense game for Android.
- Battle City - Multiplayer RTS in which you control a tank and your mission is to destroy enemy cities while defending your own.
- Bos Wars - Sci-fi RTS game.
- Castle-Combat - Clone of the arcade game Rampart.
- Dominus - Multiplayer social strategy game. Source code
- Freeciv (GNU/Linux, Windows) - A clone of Civilization II from the Sid Meier's Civilization series.
- FreeCol - Clone of Colonization
- Free Mars - Turn based strategy game about colonizing Mars.
- FreeOrion - Clone of Master of Orion
- Gigalomania - RTS MegaLoMania-like god game.
- Globulation 2 - RTS featuring auto-tasking to units.
- Julius - Re-implementation of Caesar III.
- Liberation Circuit - Rogue A.I. Simulator.
- Master of Magic/IME - Open source multiplayer Java rewrite of Simtex's classic game Master of Magic
- MAXR - Remake of the real-time/turn-based strategy game M.A.X.
- Mr.Boom, SDL Bomber and Bombermaaan - Bomberman clones.
- Megaglest - RTS where you control the armies of one of seven different factions
- Necro - A text based Virus simulator similar to Plague Inc. Source code
- OpenRA - Open-Source implementation of C&C: Red Alert, Tiberian Sun, and Dune 2000
- Spring: 1944 - RTS game set in the final year of WWII.
- Spring RTS - RTS game engine that has a few complete games made from it, like Zero-K
- Seven Kingdoms: Ancient Adversaries - GPL release of Seven Kingdoms: Ancient Adversaries
- Tanks of Freedom - Turn based strategy, similar to Advance Wars on the GBA.
- The Battle For Wesnoth (GNU/Linux, Windows, Mac, Android & iOS) - a turn-based strategy game with a high fantasy theme.
- The Last Stand
- TripleA - Game based on Axis & Allies board game.
- OpenXcom and Xenowar - Clones of the X-Com series. UFO: Alien Invasion and UFO2000 - X-Com clones.
- Warzone 2100 - 3D RTS that offers campaign, multi-player, and single-player skirmish modes.
- webDiplomacy - Online version of the game Diplomacy. Source code
- Widelands (GNU/Linux, BSD, Windows & Mac) - A real-time strategy game focused on building an economy. Based on Settlers 2.
- Wyrmsun - An interesting fantasy RTS
- Armagetron Advanced - Multiplayer 3D clone of Tron.
- BZFlag - 3D online multi-player tank battle game.
- OpenC1 - Remake of Carmageddon
- november - Short horror/escape room/walking simulator.
- Slave Of God - Trippy psychedelic ride simulator.
- Wave Function Collapse - Infinite, procedurally generated city, assembled out of blocks.
- you used to be someone - Based on the developer experience having a major depressive episode.