Prism Launcher is a custom launcher for Minecraft that focuses on predictability, long term stability and simplicity.
      Features:
      
        Easily install game modifications, such as Fabric, Forge and Quilt
        Easily install and update modpacks from the Launcher
        Control your Java settings, and enable Mangohud or Gamemode with a toggle
        Manage worlds and resource packs from the launcher
        See logs and other details easily through a dashboard
        Kill Minecraft in case of a crash/freeze
        Isolate Minecraft instances to keep everything clean
        Install and update mods directly from the launcher
        Customize the launcher with themes, and more
        And cat :3
      
    

Prism Launcher

A custom launcher for Minecraft that allows you to easily manage multiple installations of Minecraft at once

Run and jump through multiple worlds, fight off enemies by jumping on them, bumping them from below or tossing objects at them, grabbing power-ups and other stuff on the way.In addition to the Story Mode, there is a large amount of community contributed levels available as add-ons or in the forums. Everyone can contribute such content by using the integrated level editor.

SuperTux

A jump-and-run game starring Tux the Penguin

Xonotic is a free and fast-paced first person shooter which combines addictive, arena-style gameplay with rapid movement and a wide array of weapons.Xonotic is easy to learn, but hard to master! Besides thrilling action for the casual player, the game also provides e-sport opportunities for those interested in its competitive aspects. From mapping contests and monthly quick cups to sponsored tournaments, Xonotic allows every e-sport enthusiast to participate in competitions hosted by its open-minded community.Features such as simple items, fully customizable configs and servers, a functioning anticheat system, the spectator mode, and the opportunity to watch and record games makes Xonotic attractive to competitive players.

Xonotic

Multiplayer, deathmatch oriented first person shooter


      DevilutionX is a source port of Diablo and Hellfire that strives to make it simple to run the game while providing engine improvements, bugfixes, and some optional quality of life features. This includes support for modern operating systems and higher resolutions, controller and touch control support, translations, stash, optional experience and enemy health bars, etc.
		
      
      Note: DevilutionX requires data files from original Diablo/Hellfire. By default, a demo version of Diablo is installed.
		
      
	  To install the full version of Diablo, copy DIABDAT.MPQ from the CD or GOG-installation (or extract it from the GoG installer) to ~/.var/app/org.diasurgical.DevilutionX/data/diasurgical/devilution.
		
      
	  To run the Diablo: Hellfire expansion you will need to also copy hellfire.mpq, hfmonk.mpq, hfmusic.mpq, hfvoice.mpq.
		
    

DevilutionX

Cave Story NX is a nostalgic side-action adventure game to jump and shoot, using the modified NXEngine-evo engine.NXEngine-evo is a somewhat updated/refactored version of NXEngine.Cave Story was originally created by Daisuke "Pixel" Amaya

Cave Story NX

OpenSpades is a clone of Ace of Spades 0.75, which is a free online first-person shooter created by Ben Aksoy, featuring fully destructible terrain and plenty of game modes (including the well-known Capture the Flag) created by the community.Can connect to a vanilla/pyspades/pysnip serverUses OpenGL/AL for better experienceOpen source, and cross platform

OpenSpades

A fun 2D retro platformer inspired by Sonic games and a game creation system that lets you unleash your creativity!Make your dreams come true! Create your own amazing games and learn how to code with SurgeScript, a scripting language for games that is fun to use! Create new levels, items, bosses, playable characters, gameplay mechanics, cutscenes and more!Surge the Rabbit is fun for all ages! You will stop the global takeover planned by evil wizard Gimacian the Dark in a fantastic adventure! ...and you will also get to create your own games with our open source game engine!

Surge the Rabbit

A fun 2D retro platformer inspired by Sonic games and a game creation system

ioquake3 is a free and open-source software first person shooter engine based on the Quake 3: Arena and Quake 3: Team Arena source code.The source code is licensed under the GPL version 2, and was first released under that license by id software on August 20th, 2005. Since then, our dedicated team has been working hard to improve it, fixing bugs, and adding just the right new features to make the engine even better than before.

ioquake3

Free and open-source Quake 3 based engine

Blade of Agony is a story-driven FPS. The project is inspired by WWII shooters from the 90's and early 2000's, like Wolfenstein 3D, Medal of Honor, and Call of Duty, but with faster-paced gameplay in the spirit of Doom! The game can be played standalone using the GZDoom engine as a base.STORY

It's 1942, and the war approaches its peak. The U.S. has joined the Allied forces, and the Soviets are pushing back the front in the east. The tides of war are turning, and Hitler's victory seems more and more beyond his grasp. But the Nazis, refusing to capitulate, have grown obsessed with human experiments and occult artifacts, in which they see a potential escape from their final Doom. The Allied leaders reject this possibility as nonsense; nonetheless, some still fear what the Führer might be up to. The situation is nebulous, however, and little is certain.You are Cpt. William "B.J." Blazkowicz, an Allied spy, a fearless risk-taker, and the greatest soldier to ever take up arms in World War II. Your role has changed, though; you've retired from active duty, and now you spearhead operations as a systems analyst. You thought it would be the right choice--leading and motivating instead of doing the dirty work--but lately you've grown restless. At least until a few days ago, when you received an encrypted message from your old friend and comrade Cpt. Douglas Blake, calling you back to duty...FEATURES

Blade of Agony is much more than just a pastiche of the classic shooters that inspired it; the project will offer a unique experience. It also has many features not often seen in source port projects--Blade of Agony truly pushes GZDoom to its limits.36 playable and unique levelsOrchestra-quality game musicVoice acting and ambient soundscapesA combination of low-poly models and hi-resolution sprite assets to create the perfect retro feelingDevastating armaments from the battlefields of WWIIInteractive NPCs that support the twisted plot's progress and help you understand the gameBeautiful special effects (weather, elements, explosions, etc.)Achievements system similar to those seen on SteamLauncher which supports external addonsMuch, much more!

Wolfenstein: Blade of Agony

Story-driven FPS inspired by WWII shooters from the 90's and early 2000's

Cube 2: Sauerbraten is a free multiplayer &amp; singleplayer first person shooter, the successor of the Cube FPS.Much like the original Cube, the aim of this game is fun, old school deathmatch gameplay and also to allow map/geometry editing to be done cooperatively in-game.

Sauerbraten

Free multiplayer & singleplayer first person shooter, the successor of the Cube FPS

Chocolate Doom is a conservative, historically-accurate Doom source port, which is compatible with the thousands of mods and levels that were made before the Doom source code was released.  Unlike other source ports, the goal is to preserve the original look, feel, limitations, and bugs of the original DOS executable.Full support for single- and multi-player games is provided, for all of the original Doom games, Chex Quest, and Hacx.  Unlike the original executable, network play is implemented on the IP network stack, allowing it to function on modern LANs and the Internet.

Chocolate Doom

Crispy Doom is a conservative, historically-accurate Doom source port, which is compatible with the thousands of mods and levels that were made before the Doom source code was released.  Unlike other source ports, the goal is to preserve the original look, feel, limitations, and bugs of the original DOS executable.Full support for single- and multi-player games is provided, for all of the original Doom games, Chex Quest, and Hacx.  Unlike the original executable, network play is implemented on the IP network stack, allowing it to function on modern LANs and the Internet.The easiest way to run Crispy Doom is to copy a supported game file (known as a "WAD") to the root of your home directory and launch the application.  If you have trouble with the automatic game file detection or need to manage multiple WAD files, you can run the application from the command line with a path to the selected game file:flatpak run io.github.fabiangreffrath.Doom -iwad ~/PATH/TO/GAME.WAD

Crispy Doom

Limit-removing enhanced-resolution Doom source port

Freedoom: Phase 1 contains four episodes, nine levels each, to provide a smoothly-paced first person action game.  In it is a wide variety of mazes and enemies to fight and challenge your reflexes.The Freedoom project aims to produce three base-game data files (IWADs) for Doom-compatible engines.  With it comes the capability to also play the wide range of mods created for Doom by a vibrant community.  Freedoom: Phase 1 is fully compatible with The Ultimate Doom mods.

Freedoom: Phase 1

First-person shooter based on the Doom engine

Unreal Tournament 2004 is a multiplayer first person shooter that combines the kill-or-be-killed experience of gladiatorial combat with cutting-edge technology. Ten game modes provide even the most hardcore gamer with palm-sweating challenges through unbelievably detailed indoor arenas and vast outdoor environments. As the ultimate techno-gladiator of the future, players will take their fates into their hands, battling against up to 32 other players online in action-packed, frag-filled arenas.This launcher sets up the native Linux port of Unreal Tournament 2004 with additional fixes that make it work on a modern system. It needs the official game files to function properly.NOTE: This wrapper is not verified by, affiliated with, or supported by Epic Games.

Unreal Tournament 2004 Launcher


      OpenArena is a free and open source first-person shooter game based
      heavily on the Quake III Arena-style deathmatch.
      Score frags to win the game using a balanced set of weapons each designed
      for different situations.
      Guns include a chaingun, rocket launcher, shotgun, and railgun.
    
      
      OpenArena's style of play is very fast and requires skill to be played
      successfully online.
      Gameplay modes include Deathmatch, Team Deathmatch, Tournament, Capture
      the Flag, Elimination, CTF Elimination, Last Man Standing and Double
      Domination.
    
      
      This version of OpenArena is based on the Quake3e engine by "Ec" on GitHub,
      we do not take credit for his work or any of the work done by the OpenArena team.
      This Flatpak was made to be a replacement of the original one released in 2012,
      as it contains bugs and annoyances not present in this engine.
      The gameplay is 100% compatible and if not, please make
      an issue in our repo, we'll investigate it.
    
    

OpenArena (Quake3e)

Free and open source first-person shooter

AssaultCube is a free, multiplayer, first-person shooter game, based on the CUBE engine.Taking place in realistic environments, with fast, arcade gameplay, it's addictive and fun!With efficient bandwidth usage, it's low-latency and can even run over a 56 Kbps connection. It's tiny too and on the correct settings, it can even run on old hardware (Pentium III and above).

AssaultCube

ET: Legacy is a downloadable, free-to-play multiplayer game in which players wage war as Axis or Allies in team-based combat. It's a team game; you will win or fall along with your comrades. The only way to complete the objectives that lead to victory is by cooperation, with each player covering their teammates and using their class special abilities in concert with the others.
      Featuring multiplayer support for up to 64 players, ET: Legacy is the ultimate test of communication and teamwork on the battlefield. Players join the fray as one of five distinct character classes each with unique combat abilities. Each Axis or Allies team can divide itself into smaller fire teams for quick and easy communication using an intuitive messaging system and dynamic command map of the entire battlefield.
    

ET: Legacy

ET: Legacy is an open source project based on the code of Wolfenstein: Enemy Territory which was released in 2010 under the terms of the GPLv3.

Freedoom: Phase 2 is a 32-level game, expanding upon Phase 1 and adding a double-barrelled shotgun and more enemy types, along with even more brutal gameplay to really test your limits.The Freedoom project aims to produce three base-game data files (IWADs) for Doom-compatible engines.  With it comes the capability to also play the wide range of mods created for Doom by a vibrant community.  Freedoom: Phase 2 is fully compatible with Doom II mods.

Freedoom: Phase 2


      In Armagetron Advanced, you ride a bizarre vehicle that can never stop and leaves a deadly trail behind. In the most basic game mode, you can only make sudden right angle turns and are trapped with others in an inescapable arena. The last survivor wins.
    
      
      Focus is firmly on online play. Pick a server that sounds fun from the server browser, hop in, stay and play there for as long as you like with the same people. Online, you will find many variations of the core gameplay principle. There are other objectives than mere survival. In Fortress Mode, two teams face each other. Each team owns a Fortress Zone and needs to defend it while trying to conquer the enemy teams' Fortress. In Sumo Mode, everyone needs to stay inside a shrinking circle to stay alive.
    
      
      The game supports custom maps (sadly without an editor) and just about every gameplay variable can be tweaked to your, or more likely, the server owner's heart content. Speed, map size, trail length and timeouts are just the start. Even the rigid right angle turn rule can be bent!
    
    

Armagetron Advanced


      An old-school 2D platform game, starring a certain quixotic frog.
      Frogatto has gorgeous, high-end pixel art, pumping arcade tunes, and
      all the gameplay nuance of a classic console title. Run and jump over
      pits and enemies. Grab enemies with your tongue, swallow them, and then
      spit them out at other enemies as projectiles! Fight dangerous bosses,
      and solve vexing puzzles. Collect coins and use them to buy upgrades
      and new abilities in the store. Talk to characters in game, and work
      to unravel Big Bad Milgram's plot against the townsfolk!
    
    

Frogatto & Friends

OpenArena is a free and open source first-person shooter game based heavily on the Quake III Arena-style deathmatch. Score frags to win the game using a balanced set of weapons each designed for different situations. Guns include a chaingun, rocket launcher, shotgun, and railgun.OpenArena's style of play is very fast and requires skill to be played successfully online. Gameplay modes include Deathmatch, Team Deathmatch, Tournament, Capture the Flag, Elimination, CTF Elimination, Last Man Standing and Double Domination.

OpenArena

Red Eclipse is a fun-filled new take on the first person arena shooter, built as a total conversion of Cube Engine 2, which lends itself toward a balanced gameplay, with a general theme of agility in a variety of environments.Cross-platform multiplayerFeatures parkour, impulse boosts, dashing, and other tricksFavourite gamemodes with an array of mutators and variablesBuiltin editor lets you create your own maps cooperatively online

Red Eclipse

First-person shooter with agile gameplay and built-in editor

This is an SDL port of the original game from 1995. It is a run and gun game which features pixel based lighting.

Abuse

The Doomsday Engine is a portable version of the classic first person shooters DOOM, Heretic, and Hexen. It lets you enjoy the original games using modern technology, including high-resolution OpenGL graphics, 3D models, and dynamic lighting effects.Data files from the original games are not included; you must acquire a copy of the original games from id Software and/or Raven Software. You may also use free alternatives such as https://freedoom.github.io/.

Doomsday Engine

Enhanced source port of Doom, Heretic, and Hexen

Survival horror set on a remote island known as Fort Oasis. The island was once run by a community of coal miners which one day suddenly disappeared, leaving behind the abandoned concrete jungle to waste away.Something, clearly, has gone very wrong with this place. Upon your arrival at Fort Oasis, you receive a strange radio transmission. Someone wants to be found. Survive in 6 chapters, against over 8 horrifying fiends with a large assortment of weapons.

Total Chaos

Survival horror set on a remote island known as Fort Oasis

Tux is just getting ready to go fishing when all of a sudden, he receives a message. The message states that his home, Icy Island, has been taken over by the Snow King, and a new Fish Tax will be imposed. Tux is furious! How dare the Snow King take away his fish?! Help Tux overthrow the Snow King and stop him from taking Tux's fish away!ReTux is a libre open source action platformer loosely inspired by the Mario games, utilizing the art assets from the SuperTux project. The name "ReTux" is a play on the words "redux" and "Tux".

ReTux

Action platformer starring the Linux mascot, Tux

In Cro-Mag Rally you are a speed-hungry caveman named Brog who races through the Stone, Bronze, and Iron Ages in primitive vehicles such as the Geode Cruiser, Bone Buggy, Logmobile, Trojan Horse, and many others. Brog has at his disposal an arsenal of primitive weaponry ranging from Bone Bombs to Chinese Bottle Rockets and Heat Seeking Homing Pigeons.In addition to single-player racing where one player races against the computer, there are also several different multi-player modes including Tag, Quest for Fire, and Survival. Up to four players can play on a single computer in split-screen mode.About this port: CMR was released in 2000 by Pangea Software. It was a pack-in game on Macs that came out around that time. This is a port of the original OS 9 version of the game, made under permission from Pangea Software, Inc.

Cro-Mag Rally

The wildest racing game since man invented the wheel!

X-Moto is a side-scrolling 2D motocross platform game where the objective is to collect all the floating items in the level and proceed to the checkered finishing ball. The motocross bike that the player rides in xmoto has a lot of bounce, and the if the player hits their head on any solid object the level has to be restarted.There are hundreds of levels available in X-Moto, both included in the initial install, and downloadable from the Internet. There is also the ability to challenge fastest times with other players from around the world. and saved ghost data to visually see the runs of other players through the levels.

X-Moto

It has been three years since Rollie McFly rid the Bugdom of the evil King Thorax and his minions, but the Bugdom can still be dangerous place as our new hero Skip is about to find out. While on his way to visit his family on the far side of the Bugdom, a Bully Bee swooped down and stole Skip’s knapsack. Your job as Skip is to track down the Bully Bee and get your knapsack back. The chase takes place mostly in and around a house.You will make new friends in the Bugdom who will help you through each area. Keep an eye out for Sam the Snail and Sally the Chipmunk. Sam will usually make you prove your worthiness before he will help you, but Sally is just interested in gathering acorns, so be sure to brings lots of those to her. Additionally, the same Buddy Bugs that helped Rollie McFly defeat King Thorax will help you defeat most mean enemy bugs that you encounter.About this port: Bugdom 2 was released in 2002 by Pangea Software. This port aims to provide the best way to experience the game today. This port was made and re-released under permission from Pangea Software, Inc.

Bugdom 2

Track down the Bully Bee and get your knapsack back!

SeriousSamClassic is open source game engine version developed by Croteam for Serious Sam Classic, but it should work on (or be easily portable to) any system that supports OpenGL 1.3 and SDL2.Note that while the Serious-Engine source code has been released under GPL, you still need to legally own the game and provide Serious Sam Classic The First Encounter and Serious Sam Classic The Second Encounter the game data to play. See the How to Install section for more information.