Free Space Sim Games on Steam
Steam currently has 1,160 Space Sim games available to download and play. Explore our list of the best free games ranked by popularity and ratings. Data for this list is calculated from reviews and player counts reported directly by Steam and will be updated in real-time. Free Space Sim game rankings were last updated on 4/14/2025.
Looking for more? Explore other lists such as:
- Best space sim games on Steam
- Best space sim Steam Deck games
- Best space sim Steam games for Mac OS
- Best space sim Linux games on Steam
- Free Steam games
- Most played Steam games
- Best rated Steam games
1. Galaxy Idle Clicker
Embark on an interstellar journey with Galaxy Idle Clicker! Conquer galaxies, upgrade your spaceship, and face off against a myriad of enemy ships. With engaging minigames, powerful upgrades, GIC delivers an unparalleled idle space adventure. Join the cosmic conquest today and dominate the universe!
Galaxy Idle Clicker holds the #1 spot for "best free Space Sim game on Steam" with a Player Score of 72. Its score was calculated by analyzing a total of 624 reviews on Steam. This breaks down to a total of 475 positive reviews and 149 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Galaxy Idle Clicker on the Steam Deck (though some functionality may be limited).
2. Naval Action
Or were you deaf or were you blind when you left your two fine legs behind, Or was it sailing on the sea when you got the cannonball to your knee, I too was young and I was slim and I had a leg for every limb, But now I’ve got no legs at all, they were both shot away by a cannonball.
Naval Action has achieved a Player Score of 56, placing it in the #2 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 13,002 reviews on Steam. This breaks down to a total of 7,284 positive reviews and 5,718 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Naval Action on the Steam Deck.
| Release Date | 6/13/2019 |
| Franchise | Game Labs, Inc |
| Developers | |
| Publishers | |
| Steam App Id | 311310 |
3. Idle Sphere
Stunning sphere-themed idle/incremental game. Experience simplicity's beauty.
Idle Sphere has achieved a Player Score of 54, placing it in the #3 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 234 reviews on Steam. This breaks down to a total of 129 positive reviews and 105 negative reviews — making it "Mixed" on Steam.
It can be played and ran on both Windows and Mac systems. At the moment, it is not possible to play or run Idle Sphere on the Steam Deck.
| Release Date | 11/17/2024 |
| Developers | |
| Publisher | Idle System, Inc. |
| Steam App Id | 3217600 |
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 has achieved a Player Score of 89, placing it in the #4 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 6,579 reviews on Steam. This breaks down to a total of 6,074 positive reviews and 505 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play Endless Sky on the Steam Deck (though some functionality may be limited).
| Release Date | 10/30/2015 |
| Developer | Michael Zahniser |
| Publisher | Michael Zahniser |
| Steam App Id | 404410 |
5. Infinite Lagrange
Different forces strive to make their own way in the space and desire the control of the Lagrange system- a gigantic transportation network. You, emerging as one of the force leaders, find yourself in a time of challenges and opportunities.
Infinite Lagrange has achieved a Player Score of 56, placing it in the #5 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 864 reviews on Steam. This breaks down to a total of 487 positive reviews and 377 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Infinite Lagrange on the Steam Deck.
| Release Date | 10/8/2021 |
| Developer | NetEase Games |
| Publisher | NetEase Games |
| Steam App Id | 1755920 |
6. Nova: Space Armada
An exceptional sci-fi strategy game based on space adventure as its core.
Nova: Space Armada has achieved a Player Score of 51, placing it in the #6 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 75 reviews on Steam. This breaks down to a total of 39 positive reviews and 36 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, there is no confirmed information regarding Steam Deck support for this game.
| Release Date | 10/22/2024 |
| Developer | STONE3 PTE. LTD. |
| Publisher | STONE3 PTE. LTD. |
| Steam App Id | 1108270 |
7. Star Conflict
Star Conflict is an action-packed, massively multiplayer space simulation game that puts players in the role of elite pilots engaging in a widespread interplanetary skirmish. The whole world for PVP and PVE!
Star Conflict has achieved a Player Score of 72, placing it in the #7 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 14,813 reviews on Steam. This breaks down to a total of 10,866 positive reviews and 3,947 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play Star Conflict on the Steam Deck (though some functionality may be limited).
| Release Date | 2/27/2013 |
| Franchise | Gaijin Network Ltd |
| Developer | Star Gem Inc. |
| Publishers | |
| Steam App Id | 212070 |
8. Starborne: Frontiers
Starborne: Frontiers is a free-to-play tactical autobattler with hundreds of unique ships. Form your fleet, customize it with a variety of equipment, and use strategy to create the perfect battlefield formation. Take on bounties, engage in the PvP arena, and bring order to the Frontier.
Starborne: Frontiers has achieved a Player Score of 64, placing it in the #8 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 233 reviews on Steam. This breaks down to a total of 158 positive reviews and 75 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, there is no confirmed information regarding Steam Deck support for this game.
| Release Date | 10/14/2024 |
| Developer | Solid Clouds hf. |
| Publisher | Solid Clouds hf. |
| Steam App Id | 3021540 |
9. Nova Empire
Build up a Space Empire and establish control of the Galaxy and the Universe! Nova Empire is a multiplayer space game in which the aim is to build your empire and conquer the galaxy in epic space battles against your rivals with other allies worldwide!
Nova Empire has achieved a Player Score of 53, placing it in the #9 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 243 reviews on Steam. This breaks down to a total of 131 positive reviews and 112 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, there is no confirmed information regarding Steam Deck support for this game.
| Release Date | 5/26/2022 |
| Developer | Gamebear Tech |
| Publisher | Gamebear Tech |
| Steam App Id | 1962770 |
10. 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 has achieved a Player Score of 72, placing it in the #10 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 882 reviews on Steam. This breaks down to a total of 664 positive reviews and 218 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is not possible to play or run Prosperous Universe on the Steam Deck.
| Release Date | 4/20/2022 |
| Developer | simulogics |
| Publisher | simulogics |
| Steam App Id | 1761220 |
More Free Space Sim Games
Explore even more rankings for the 100 best free Space Sim games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 1,229 | 7/18/2024 | 72 | Free | Steam Charts | |
| 781 | 6/13/2019 | 56 | Free | Steam Charts | |
| 166 | 11/17/2024 | 54 | Free | Steam Charts | |
| 121 | 10/30/2015 | 89 | Free | Steam Charts | |
| 95 | 10/8/2021 | 56 | Free | Steam Charts | |
| 82 | 10/22/2024 | 51 | Free | Steam Charts | |
| 69 | 2/27/2013 | 72 | Free | Steam Charts | |
| 60 | 10/14/2024 | 64 | Free | Steam Charts | |
| 34 | 5/26/2022 | 53 | Free | Steam Charts | |
| 32 | 4/20/2022 | 72 | Free | Steam Charts | |
 | 28 | 6/12/2020 | 64 | Free | Steam Charts | |
 | 23 | 5/4/2021 | 81 | Free | Steam Charts | |
 | 17 | 9/22/2020 | 61 | Free | Steam Charts | |
 | 11 | 9/25/2024 | 76 | Free | Steam Charts | |
 | 8 | 2/11/2024 | 83 | Free | Steam Charts | |
 | 7 | 7/18/2024 | 47 | Free | Steam Charts | |
 | 7 | 1/22/2021 | 61 | Free | Steam Charts | |
 | 6 | 2/12/2024 | 83 | Free | Steam Charts | |
 | 6 | 11/4/2020 | 65 | Free | Steam Charts | |
 | 5 | 12/8/2024 | 70 | Free | Steam Charts |
Soures & References
Steambase has best-in-class data powered directly by Steam, our data partners, and in-house experts. Player counts and rankings are enriched, analyzed, and updated in real-time to ensure we surface the most up-to-date insights. Learn more about the Steambase approach to data collection and our review methodology.
- Valve Corporation. (2025, April 14). Steam Store. Steam Store.
- Valve Corporation. (2025, April 14). Galaxy Idle Clicker on Steam. Steam Store.
- Valve Corporation. (2025, April 14). Naval Action on Steam. Steam Store.
- Valve Corporation. (2025, March 14). Idle Sphere on Steam. Steam Store.
- Valve Corporation. (2025, March 24). Endless Sky on Steam. Steam Store.
- Valve Corporation. (2025, March 22). Infinite Lagrange on Steam. Steam Store.
- Valve Corporation. (2025, April 14). Nova: Space Armada on Steam. Steam Store.
- Valve Corporation. (2025, April 14). Star Conflict on Steam. Steam Store.
- Valve Corporation. (2025, April 14). Starborne: Frontiers on Steam. Steam Store.
- Valve Corporation. (2025, April 14). Nova Empire on Steam. Steam Store.
- Valve Corporation. (2025, March 13). Prosperous Universe on Steam. Steam Store.