Check out this fantastic list of free-to-play sci-fi games you can enjoy on Steam right now, updated on May 16th 2026. Looking for even more free titles? Explore the complete list of the best free to play sci-fi games on Steam.
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1. Star Trek Online
In Star Trek Online, the Star Trek universe appears for the first time on a truly massive scale. Players take the captain's chair as they command their own starship and crew. Explore strange new worlds, seek out new life and new civilizations, and boldly go where no one has gone before. Star Trek Online is a sci-fi, massively multiplayer and space game. Released on January 31st 2012 has received 20,145 reviews of which 15,939 were positive and 4,206 were negative resulting in a rating of 7.8 out of 10. The game has hit the top spot as the #1 most played sci-fi game, thanks to its 1,215 peak concurrent players over the last day.
7.8
15,939
4,206
1,215
players
2. Star Trek Timelines
Explore the Final Frontier in the ultimate sci-fi strategy RPG, Star Trek Timelines! Join Starfleet and overcome challenges as you boldly go where no game has gone before – across the entire history of Star Trek. Star Trek Timelines is a strategy, space and adventure game. Released on July 12th 2017 has received 1,430 reviews of which 938 were positive and 492 were negative resulting in a rating of 6.4 out of 10. While seeing 179 players online at once in the last 24 hours, this game is currently ranked #2 among sci-fi games based on player count.
6.4
938
492
179
players
3. Odysseus Kosmos and his Robot Quest: Episode 1
What do you do if you are the only one left aboard a spaceship? Your team has embarked on a mysterious expedition a few years ago, the ship’s machinery has started acting up and it seems there are ghosts wandering about. Luckily, the black hole above you doesn’t pose any problems…yet. Odysseus Kosmos and his Robot Quest: Episode 1 is a indie, sci-fi and point & click game. Released on January 12th 2018 has received 484 reviews of which 381 were positive and 103 were negative resulting in a rating of 7.4 out of 10. While seeing 128 players online at once in the last 24 hours, this game is currently ranked #3 among sci-fi games based on player count.
7.4
381
103
128
players
4. Endless Sky
Endless Sky is a 2D space trading and combat game inspired by the classic Escape Velocity series. Work your way up from a relatively wimpy shuttle, cargo ship, or fighter, to a highly upgraded and customized flagship or to a massive fleet of warships or freighters. Endless Sky is a space, open world and singleplayer game. Released on October 30th 2015 has received 6,651 reviews of which 6,141 were positive and 510 were negative resulting in a rating of 8.9 out of 10. With 116 concurrent players in the last 24 hours, the game currently holds the #4 spot among the most played sci-fi games.
8.9
6,141
510
116
players
5. Hades' Star
A unique space strategy game where thousands of players participate in one shared galaxy. Hades' Star is a space, strategy and massively multiplayer game. Released on February 27th 2019 has received 2,577 reviews of which 1,874 were positive and 703 were negative resulting in a rating of 7.1 out of 10. The game currently holds the #5 spot among the most played sci-fi games.
7.1
1,874
703
92
players
6. Pixel Starships
Pixel Starships is an FTL-style online sci-fi strategy builder and management game with a competitive PVP tournament. Set in the retro galaxy, your role is to explore space, meet aliens, and develop your ship, crew and AI. The game contains deep strategic and 4x elements. PSS is community-driven. Pixel Starships is a sci-fi, space and strategy game. Released on May 23rd 2023 has received 2,732 reviews of which 2,008 were positive and 724 were negative resulting in a rating of 7.1 out of 10. The game currently holds the #6 spot among the most played sci-fi games.
7.1
2,008
724
88
players
7. AX:EL - Air XenoDawn
Combining the very best of sci-fi and aerial dogfighting gameplay, AX:EL delivers a totally new gaming experience. Create your very own shape-shifting vehicle and dominate both the sky and the ocean. AX:EL - Air XenoDawn is a action, indie and simulation game. Released on December 04th 2015 has received 1,192 reviews of which 899 were positive and 293 were negative resulting in a rating of 7.2 out of 10. The game currently holds the #7 spot among the most played sci-fi games.
7.2
899
293
29
players
8. Prosperous Universe
In Prosperous Universe start your galactic empire by trading on the real-time market exchange with other real players. Build your 1st base from humble beginnings & watch as your business flourishes with complex supply chain strategies. Economics, politics & realism fuel this immersive business MMO. Prosperous Universe is a early access, economy and resource management game. Released on April 20th 2022 has received 1,062 reviews of which 779 were positive and 283 were negative resulting in a rating of 7.1 out of 10. The game currently holds the #8 spot among the most played sci-fi games.
7.1
779
283
22
players
9. Buy a Croquette!
March 2012, Nagano. The brave and clever high school girl, Chio Aozora, is facing a major crisis: she doesn’t have enough money to buy a croquette! Navigate through the streets and alleys of Nagano, interact with a variety of characters, solve complex puzzles, collect 380 yen, and buy a croquette! Buy a Croquette! is a rpgmaker, mystery and sci-fi game. Released on April 27th 2024 has received 4,397 reviews of which 4,355 were positive and 42 were negative resulting in an impressive rating of 9.5 out of 10. The game currently holds the #9 spot among the most played sci-fi games.
9.5
4,355
42
11
players
10. Toaster Arena
Toaster Arena is a first person multiplayer arena shooter where players battle it out on different maps and game modes. Use Advanced movement to traverse obstacles and gain the advantage on the battlefield. Toaster Arena is a early access, action and fps game. Released on January 20th 2025 has received 704 reviews of which 647 were positive and 57 were negative resulting in a rating of 8.6 out of 10. The game currently holds the #10 spot among the most played sci-fi games.
8.6
647
57
9
players
More Sci-fi & Related Games
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