Free Space Sim Games on Steam
Steam currently has 1,128 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 2/18/2025.
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 73. Its score was calculated by analyzing a total of 554 reviews on Steam. This breaks down to a total of 429 positive reviews and 125 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. Idle Sphere
Stunning sphere-themed idle/incremental game. Experience simplicity's beauty.
Idle Sphere 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 207 reviews on Steam. This breaks down to a total of 117 positive reviews and 90 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 |
3. 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 #3 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 12,718 reviews on Steam. This breaks down to a total of 7,229 positive reviews and 5,489 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 |
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 840 reviews on Steam. This breaks down to a total of 473 positive reviews and 367 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. 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 #5 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 6,520 reviews on Steam. This breaks down to a total of 6,021 positive reviews and 499 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 |
6. 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 #6 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 206 reviews on Steam. This breaks down to a total of 141 positive reviews and 65 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 |
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 14,775 reviews on Steam. This breaks down to a total of 10,852 positive reviews and 3,923 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. 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 53, placing it in the #8 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 53 reviews on Steam. This breaks down to a total of 29 positive reviews and 24 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 |
9. 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 62, placing it in the #9 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 523 reviews on Steam. This breaks down to a total of 333 positive reviews and 190 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 |
10. 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 52, placing it in the #10 spot for the best free Space Sim games. Its score was calculated by analyzing a total of 237 reviews on Steam. This breaks down to a total of 124 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 |
More Free Space Sim Games
Explore even more rankings for the 100 best free Space Sim games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 1,277 | 7/18/2024 | 73 | Free | Steam Charts | |
| 306 | 11/17/2024 | 55 | Free | Steam Charts | |
| 122 | 6/13/2019 | 56 | Free | Steam Charts | |
| 111 | 10/8/2021 | 55 | Free | Steam Charts | |
| 100 | 10/30/2015 | 89 | Free | Steam Charts | |
| 93 | 10/14/2024 | 65 | Free | Steam Charts | |
| 86 | 2/27/2013 | 72 | Free | Steam Charts | |
| 57 | 10/22/2024 | 53 | Free | Steam Charts | |
| 49 | 9/22/2020 | 62 | Free | Steam Charts | |
| 42 | 5/26/2022 | 52 | Free | Steam Charts | |
 | 34 | 7/16/2024 | 57 | Free | Steam Charts | |
 | 24 | 4/20/2022 | 72 | Free | Steam Charts | |
 | 21 | 5/4/2021 | 81 | Free | Steam Charts | |
 | 21 | 9/25/2024 | 76 | Free | Steam Charts | |
 | 20 | 6/12/2020 | 64 | Free | Steam Charts | |
 | 12 | 2/11/2024 | 83 | Free | Steam Charts | |
 | 9 | 7/18/2024 | 49 | Free | Steam Charts | |
 | 7 | 12/8/2024 | 73 | Free | Steam Charts | |
 | 5 | 11/4/2020 | 65 | Free | Steam Charts | |
 | 5 | 10/23/2021 | 84 | 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, February 18). Steam Store. Steam Store.
- Valve Corporation. (2025, February 18). Galaxy Idle Clicker on Steam. Steam Store.
- Valve Corporation. (2025, February 18). Idle Sphere on Steam. Steam Store.
- Valve Corporation. (2025, February 19). Naval Action on Steam. Steam Store.
- Valve Corporation. (2025, January 23). Infinite Lagrange on Steam. Steam Store.
- Valve Corporation. (2025, January 25). Endless Sky on Steam. Steam Store.
- Valve Corporation. (2025, February 18). Starborne: Frontiers on Steam. Steam Store.
- Valve Corporation. (2025, February 18). Star Conflict on Steam. Steam Store.
- Valve Corporation. (2025, February 15). Nova: Space Armada on Steam. Steam Store.
- Valve Corporation. (2025, January 20). Space Travel Idle on Steam. Steam Store.
- Valve Corporation. (2025, February 5). Nova Empire on Steam. Steam Store.