Free to Play Sci-fi Games on Steam
Check out this fantastic list of free-to-play sci-fi games you can enjoy on Steam right now, updated on July 30th 2025. Looking for even more free titles? Explore the complete list of the best free to play sci-fi games.
Lists & Categories
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 game developed and published by . 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 1,325 peak concurrent players over the last day.
7.8
15,939
4,206
1,325
players
2. 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 game developed and published by . 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. While seeing 125 players online at once in the last 24 hours, this game is currently ranked #2 among sci-fi games based on player count.
7.1
2,008
724
125
players
3. 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 game developed and published by . 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. The game currently holds the #3 spot among the most played sci-fi games.
8.9
6,141
510
95
players
4. Hades' Star
A unique space strategy game where thousands of players participate in one shared galaxy. Hades' Star is a game developed and published by . 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 #4 spot among the most played sci-fi games.
7.1
1,874
703
92
players
5. 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 game developed and published by . Released on April 20th 2022 has received 910 reviews of which 685 were positive and 225 were negative resulting in a rating of 7.2 out of 10. The game currently holds the #5 spot among the most played sci-fi games.
7.2
685
225
27
players
6. 买个可乐饼吧！ - Buy a Croquette!
March 2012, Nagano. The smart and brave high school girl, Chio Aozora, is facing a major crisis: she has no 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 in coins, and buy a croquette! 买个可乐饼吧！ - Buy a Croquette! is a game developed and published by . 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 #6 spot among the most played sci-fi games.
9.5
4,355
42
18
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 game developed and published by . 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
18
players
8. 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 game developed and published by . 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. The game currently holds the #8 spot among the most played sci-fi games.
7.4
381
103
12
players
9. 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 game developed and published by . Released on January 20th 2025 has received 394 reviews of which 357 were positive and 37 were negative resulting in a rating of 8.4 out of 10. The game currently holds the #9 spot among the most played sci-fi games.
8.4
357
37
9
players
10. South Scrimshaw, Part One
South Scrimshaw is the story of a newborn whale in a vast alien ocean. It is a richly illustrated experimental visual novel, written in the style of a nature documentary. South Scrimshaw, Part One is a game developed and published by . Released on June 09th 2023 has received 1,420 reviews of which 1,409 were positive and 11 were negative resulting in an impressive rating of 9.4 out of 10. The game currently holds the #10 spot among the most played sci-fi games.
9.4
1,409
11
2
players
More Sci-fi & Related Games
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