Best Free Sci-Fi Games for PC and Browser in 2025!

Ace Online
Ace Online (Air Rivals in Europe) is an action based sci-fi MMO 3D Space Shooter with very unique PvP (up to 100 vs 100), gameplay, and wonderful graphics. The game was originally released as "Space Cowboys" in the United States.

AirMech
AirMech is a 3D sci-fi RTS by Carbon Games, available in the browser (Chrome) and through Steam With DotA-style gameplay players control a transforming mech, that can take flight at a moments notice in this strategy based game. Combat on the ground or switch to air to fly around and pick up units to transport.

Alien Swarm: Reactive Drop
Taking its cues from its predecessor, Alien Swarm: Reactive Drop is a free-to-play action shooter with a top-down view and tons of extra-terrestrial baddies to exterminate. Reactive Drop includes an extensive campaign mode, PvP, and a vast array of deadly weapons to mince and mangle with.

Anarchy Online
Anarchy Online is a 3D Sci-Fi MMORPG originally released in 2001 as a subscription based game, but it’s now available for free. Anarchy Online has four playable races (Solitus, Opifex , Nanomage, and Atrox) and fourteen different classes to chose from (Adventurer, Agent, Bureaucrat, Doctor, Enforcer, Engineer, Fixer, Keeper, Martial Artist, Meta-Physicist, Nano Technician, Shade, Soldier).

Apex Legends
Apex Legends is a free-to-play battle royale set in the Titanfall universe and taking place after the events of Titanfall 2. Following the events of the Frontier War, the bloody Apex Games are in full swing, drawing in legends from all across the Frontier to fight for fame, glory, and riches!

Astro Empires
Explore the farthest reaches of space in Cybertopia Studios’ Astro Empires, a free to play text-based space strategy MMO that gives you something you’ve always dreamed of: the chance to build your own galaxy-spanning empire among the stars. As you start with your own planet in the farthest flung regions of unknown space in Astro Empires, you will learn to gather materials and develop new technologies to turn your previously unnoticed rock into a mighty empire befitting a galactic emperor.

Awesomenauts
Fight for the future and be totally awesome in Awesomenauts, a 2-D, side-scrolling MOBA that's even better now that it's free-to-play! Play online or local multiplayer in 3v3 matches or death matches.

Brink
Splash Damage's award-winning first-person shooter Brink is now free-to-play! In the distant future, the Ark -- meant to be a self-sustaining habitat -- is overflowing with refugees and resources are scarce.

Champions Online
Champions Online: Free for All is a 3D superhero-themed Fantasy MMORPG (Massively multiplayer online role playing game) from Cryptic Studios (creator of City of Heroes Freedom), with fast paced gameplay and awesome cel-shading graphics, set in Millennium City. The game used to be pay to play but officially went free to play.

Closers
In Closers, a free-to-play fighting MMORPG, horrific creatures are springing from mysterious dimensional gates all around New Seoul, and it's up to you to stop them! Play as one of several psychic warriors, each with their own unique backstory and special abilities, and reclaim Korea!

Cosmos Invictus
Decide the fate of humanity in Cosmos Invictus, a sci-fi, free-to-play CCG from Pegnio Ltd. featuring spaceborne 'mech combat and strategies not found in most CCGs.

Crossout
Trick out your ride and take to the post-apocalyptic roads for battle in Crossout, the free-to-play vehicular combat game from Gaijin Entertainment! Featuring a vehicle design system with endless customization and fast-paced, armor-crunching combat, Crossout offers high-octane excitement in brief and explosive matches.

Dark Orbit Reloaded
Take part in huge intergalactic battles and take on the whole galaxy in DarkOrbit, the free-to-play browser-based space combat MMO from Bigpoint -- now in 3-D! Choose your faction and your ship, each with their own strengths, and take off into adventure!

Darwin Project
Experience a fresh perspective on the battle royale experience with Darwin Project, a free-to-play game that takes the "game show" concept to a whole new level. As a contestant, you'll need to craft and kill your way to the top, as usual -- but the Show Director can make your life easier, or more difficult, and spectators can also weigh in, influencing the Director to aid or hinder players of their choosing.

Destiny 2
Embark on a heroic quest to save humanity in Bungie's epic sci-fi MMO shooter Destiny 2, now free-to-play. Experience a wealth of content as a stalwart Titan, mysterious Warlock, or crafty Hunter, battling the enemies of humanity across the solar system.

Dino Storm
Dino Storm is a 3D RPG browser-based MMO by Splitscreen Studios. Players embark on a perilous journey to DinoVille, with nothing more than a change in their pockets, some ammunition, a loaded laser cannon, and your very own dinosaur.

Dreadnought
Dreadnought is a sci-fi, multi-player space combat simulator from Yager. Players will take control of a variety of unique ships to combat opposing teams in a strategic environment.

Entropia Universe
Entropia Universe is free to play 3D Sci-Fi MMORPG with interesting economic and social features. MindArk’s virtual economy universe is known by many names depending on when you started playing the game and what planet was the key planet at the time.

Fallout Shelter
Bethesda Softworks' hit mobile game comes to PC! In Fallout Shelter, you'll populate and manage the citizens of your Vault-Tec Vault, protecting them from the dangers of the Wasteland and encouraging them to rebuild society.

Fortnite
Play Fortnite in a totally new way, in Fortnite: Battle Royale, the free-to-play spinoff of Epic Games' builder/shooter. Like other classic BR games, you'll be dropped into the world and forced to scavenge and survive.

GALAHAD 3093
Hop in your Arthurian legend inspired mech and compete your way to the top of the round table.

Gear Up
Gear Up is a free to play multiplayer arcade action game with tanks and robots. Vehicular combat is fun, and Gear Up is no exception to that.

GetAmped 2
GetAmped 2 is a free fighting MMO game that follows the work made on Splash Fighters. In this game players enter the city of Wingdom and choose a fighter from five different classes.

Gundam Evolution
Miss when that other hero shooter was 6v6? Well here you can do that AND wear sweet Mobile Suits!

Guns and Robots
Guns and Robots is a third person shooter which combines silly robots and the wild west. In Guns and Robots players can create unique robots from scratch by combining over 150 individual components.

Halo Infinite (Multiplayer)
Step into the boots of a fresh Spartan and fight for galactic supremacy in free-to-play Halo Infinite Multiplayer

Holodrive
Blast some robotic butt in Holodrive, a free-to-play 2D shooter from BitCake Studio and Versus Evil. The Holocorp "Dummy" robots were designed to be man's new best friend, but they instead became murderous machines looking only to blow each other up -- and look good doing it.

Insidia
Insidia is a free-to-play turn-based tactical strategy game that pits two teams of four against each other in a post-apocalyptic -- but still colorful -- battleground. Plot out your turns and then watch your strategies unfold (or go horribly awry).

Ironsight
Ironsight is a free-to-play shooter set in the 2020s, when two factions fight over the last of the planet's dwindling resources. Built from the ground up in the Iron Engine, Ironsight offers top-notch visuals and dynamic battlefields.

Mars Tomorrow
Explore the Red Planet and save humanity in Mars Tomorrow, a free-to-play browser simulation game from Gamefabrik and Bytro Labs.

Marvel Rivals
Marvel IP and a hero-shooter, could there be a better free-to-play combo?

MechWarrior Online
MechWarrior Online is a free to play 3D simulation style multiplayer FPS mech game that captures the feeling of piloting a gigantic BattleMech. Players take control of one of a variety of towering Mechs which weight dozens of tons.