Free Space Sim Games on Steam
Steam currently has 1,191 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 5/27/2025.
Looking for more? Explore other lists such as:
- Best space sim games on Steam
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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 664 reviews on Steam. This breaks down to a total of 501 positive reviews and 163 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 55, placing it in the #2 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 13,518 reviews on Steam. This breaks down to a total of 7,421 positive reviews and 6,097 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 252 reviews on Steam. This breaks down to a total of 137 positive reviews and 115 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. 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 55, placing it in the #4 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 890 reviews on Steam. This breaks down to a total of 498 positive reviews and 392 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 |
5. 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 50, placing it in the #5 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 100 reviews on Steam. This breaks down to a total of 50 positive reviews and 50 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 |
6. 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 #6 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 14,842 reviews on Steam. This breaks down to a total of 10,873 positive reviews and 3,969 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 |
7. 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 65, placing it in the #7 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 247 reviews on Steam. This breaks down to a total of 170 positive reviews and 77 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 |
8. 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 #8 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 6,643 reviews on Steam. This breaks down to a total of 6,134 positive reviews and 509 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 |
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 54, placing it in the #9 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 248 reviews on Steam. This breaks down to a total of 135 positive reviews and 113 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. Space Travel Idle
If you ever dreamed of exploring space at a relaxed pace, here's a journey designed for you.
Space Travel Idle has achieved a Player Score of 61, placing it in the #10 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 529 reviews on Steam. This breaks down to a total of 335 positive reviews and 194 negative reviews — making it "Mixed" on Steam.
It can be played and ran on both Windows and Mac systems. At the moment, it is possible to play Space Travel Idle on the Steam Deck (though some functionality may be limited).
| Release Date | 9/22/2020 |
| Developer | Ayatsuji_San |
| Publisher | Spaceive |
| Steam App Id | 1407860 |
More Free Space Sim Games
Explore even more rankings for the 100 best free Space Sim games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 1,125 | 7/18/2024 | 72 | Free | Steam Charts | |
| 275 | 6/13/2019 | 55 | Free | Steam Charts | |
| 150 | 11/17/2024 | 54 | Free | Steam Charts | |
| 122 | 10/8/2021 | 55 | Free | Steam Charts | |
| 79 | 10/22/2024 | 50 | Free | Steam Charts | |
| 71 | 2/27/2013 | 72 | Free | Steam Charts | |
| 64 | 10/14/2024 | 65 | Free | Steam Charts | |
| 54 | 10/30/2015 | 89 | Free | Steam Charts | |
| 50 | 5/26/2022 | 54 | Free | Steam Charts | |
| 34 | 9/22/2020 | 61 | Free | Steam Charts | |
 | 31 | 5/8/2025 | 46 | Free | Steam Charts | |
 | 31 | 5/4/2021 | 81 | Free | Steam Charts | |
 | 28 | 4/20/2022 | 72 | Free | Steam Charts | |
 | 17 | 6/12/2020 | 64 | Free | Steam Charts | |
 | 16 | 2/11/2024 | 84 | Free | Steam Charts | |
 | 12 | 7/18/2024 | 50 | Free | Steam Charts | |
 | 10 | 9/2/2024 | 56 | Free | Steam Charts | |
 | 9 | 10/31/2018 | 79 | Free | Steam Charts | |
 | 6 | 1/22/2021 | 61 | Free | Steam Charts | |
 | 5 | 7/18/2023 | 81 | 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, May 27). Steam Store. Steam Store.
- Valve Corporation. (2025, May 27). Galaxy Idle Clicker on Steam. Steam Store.
- Valve Corporation. (2025, May 27). Naval Action on Steam. Steam Store.
- Valve Corporation. (2025, May 16). Idle Sphere on Steam. Steam Store.
- Valve Corporation. (2025, May 30). Infinite Lagrange on Steam. Steam Store.
- Valve Corporation. (2025, May 28). Nova: Space Armada on Steam. Steam Store.
- Valve Corporation. (2025, May 29). Star Conflict on Steam. Steam Store.
- Valve Corporation. (2025, May 28). Starborne: Frontiers on Steam. Steam Store.
- Valve Corporation. (2025, May 14). Endless Sky on Steam. Steam Store.
- Valve Corporation. (2025, May 30). Nova Empire on Steam. Steam Store.
- Valve Corporation. (2025, May 14). Space Travel Idle on Steam. Steam Store.