Free Aliens Games on Steam
Steam currently has 2,887 Aliens 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 Aliens game rankings were last updated on 8/15/2025.
Looking for more? Explore other lists such as:
- Best aliens games on Steam
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1. Unnamed Space Idle
Destroy endless waves of alien ships that have all but wiped out humanity in this long form, unfolding, sci-fi idle game. Customize your ship with different weapons and defenses to defeat specific enemy types and utilize a ton of different systems to increase your overall power.
Unnamed Space Idle holds the #1 spot for "best free Aliens game on Steam" with a Player Score of 89. Its score was calculated by analyzing a total of 3,218 reviews on Steam. This breaks down to a total of 2,988 positive reviews and 230 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is possible to play Unnamed Space Idle on the Steam Deck (though some functionality may be limited).
| Release Date | 7/27/2023 |
| Developer | Sylv |
| Publishers | |
| Steam App Id | 2471100 |
2. Halo Infinite
From one of gaming's most iconic sagas, Halo is bigger than ever. Featuring an expansive open-world campaign and a dynamic free to play multiplayer experience.
Halo Infinite has achieved a Player Score of 69, placing it in the #2 spot for the best free Aliens games. Its score was calculated by analyzing a total of 177,638 reviews on Steam. This breaks down to a total of 123,621 positive reviews and 54,017 negative reviews — making it "Mixed" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Halo Infinite on the Steam Deck (though some functionality may be limited).
| Release Date | 11/15/2021 |
| Franchise | Xbox Game Studios |
| Developer | 343 Industries |
| Publisher | Xbox Game Studios |
| Steam App Id | 1240440 |
3. Finn Dorset's Institute For Livestock Replication
An animated incremental game about cloning livestock. Make as many moon sheep as you can. Research technology, upgrade your operation and become a clone farm billionaire!
Finn Dorset's Institute For Livestock Replication has achieved a Player Score of 82, placing it in the #3 spot for the best free Aliens games. Its score was calculated by analyzing a total of 845 reviews on Steam. This breaks down to a total of 730 positive reviews and 115 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Finn Dorset's Institute For Livestock Replication on the Steam Deck (though some functionality may be limited).
| Release Date | 10/2/2024 |
| Developer | CarlMorganArt |
| Publisher | CarlMorganArt |
| Steam App Id | 3135530 |
4. Operation: New Earth
Operation: New Earth is an intense sci-fi multiplayer strategy game in which you must command an advanced military facility to defend Earth from a hostile alien invasion. Create an alliance, gather resources, and unlock advanced technology to level up your stronghold!
Operation: New Earth has achieved a Player Score of 59, placing it in the #4 spot for the best free Aliens games. Its score was calculated by analyzing a total of 784 reviews on Steam. This breaks down to a total of 473 positive reviews and 311 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 Operation: New Earth on the Steam Deck (though some functionality may be limited).
| Release Date | 12/14/2016 |
| Developers | |
| Publishers | |
| Steam App Id | 528740 |
5. Galaxy Life
The universe is full of Starlings, tiny orange aliens that want to take over the galaxy. Create your own space colony, fight epic battles and discover new planets. Train your soldiers, develop your technology and create unimaginable gadgets. Enjoy this huge social game with friends!
Galaxy Life has achieved a Player Score of 89, placing it in the #5 spot for the best free Aliens games. Its score was calculated by analyzing a total of 8,113 reviews on Steam. This breaks down to a total of 7,421 positive reviews and 692 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is possible to play Galaxy Life on the Steam Deck (though some functionality may be limited).
| Release Date | 8/31/2022 |
| Developer | Phoenix Network |
| Publisher | Phoenix Network |
| Steam App Id | 1927780 |
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 has achieved a Player Score of 71, placing it in the #6 spot for the best free Aliens games. Its score was calculated by analyzing a total of 2,774 reviews on Steam. This breaks down to a total of 2,037 positive reviews and 737 negative reviews — making it "Mostly Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. Valve has also verified it as playable on the Steam Deck and will run well.
7. Project Entropy
Welcome, commander, to Project Entropy- an ultimate Sci-Fi and role-playing game with battles in space. In this immersive MMO experience, you will command alien civilizations, conquer uncharted planets, and build Hero fleets.
Project Entropy has achieved a Player Score of 52, placing it in the #7 spot for the best free Aliens games. Its score was calculated by analyzing a total of 157 reviews on Steam. This breaks down to a total of 83 positive reviews and 74 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 Project Entropy on the Steam Deck.
| Release Date | 4/17/2024 |
| Developer | FunPlus International AG |
| Publisher | FunPlus International AG |
| Steam App Id | 2806410 |
8. 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 #8 spot for the best free Aliens games. Its score was calculated by analyzing a total of 14,899 reviews on Steam. This breaks down to a total of 10,875 positive reviews and 4,024 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 |
9. Alien Swarm: Reactive Drop
Co-operative top-down shooter game available for free. An epic bug hunt featuring a unique blend of co-op play and squad-level tactics.
Alien Swarm: Reactive Drop has achieved a Player Score of 93, placing it in the #9 spot for the best free Aliens games. Its score was calculated by analyzing a total of 22,858 reviews on Steam. This breaks down to a total of 21,700 positive reviews and 1,158 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Alien Swarm: Reactive Drop on the Steam Deck.
| Release Date | 4/20/2017 |
| Developer | Reactive Drop Team |
| Publisher | Reactive Drop Team |
| Steam App Id | 563560 |
10. Entropy : Zero 2
Bad Cop is back. Command a small army of Combine synths and soldiers on a Northern campaign to capture Dr. Judith Mossman. A modification for Half-Life 2.
Entropy : Zero 2 has achieved a Player Score of 96, placing it in the #10 spot for the best free Aliens games. Its score was calculated by analyzing a total of 29,292 reviews on Steam. This breaks down to a total of 28,803 positive reviews and 489 negative reviews — making it "Overwhelmingly Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is possible to play Entropy : Zero 2 on the Steam Deck (though some functionality may be limited).
More Free Aliens Games
Explore even more rankings for the 100 best free Aliens games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 4,548 | 7/27/2023 | 89 | Free | Steam Charts | |
| 2,423 | 11/15/2021 | 69 | Free | Steam Charts | |
| 318 | 10/2/2024 | 82 | Free | Steam Charts | |
| 307 | 12/14/2016 | 59 | Free | Steam Charts | |
| 230 | 8/31/2022 | 89 | Free | Steam Charts | |
| 194 | 5/23/2023 | 71 | Free | Steam Charts | |
| 192 | 4/17/2024 | 52 | Free | Steam Charts | |
| 85 | 2/27/2013 | 72 | Free | Steam Charts | |
| 80 | 4/20/2017 | 93 | Free | Steam Charts | |
| 80 | 8/20/2022 | 96 | Free | Steam Charts | |
 | 69 | 12/15/2022 | 87 | Free | Steam Charts | |
 | 40 | 3/27/2015 | 91 | Free | Steam Charts | |
 | 26 | 9/16/2022 | 94 | Free | Steam Charts | |
 | 22 | 7/28/2025 | 69 | Free | Steam Charts | |
 | 19 | 7/19/2010 | 93 | Free | Steam Charts | |
 | 19 | 1/29/2025 | 51 | Free | Steam Charts | |
 | 14 | 7/31/2025 | 55 | Free | Steam Charts | |
 | 12 | 2/23/2021 | 71 | Free | Steam Charts | |
 | 12 | 6/9/2024 | 91 | Free | Steam Charts | |
 | 11 | 3/28/2024 | 59 | 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, August 15). Steam Store. Steam Store.
- Valve Corporation. (2025, August 15). Unnamed Space Idle on Steam. Steam Store.
- Valve Corporation. (2025, August 19). Halo Infinite on Steam. Steam Store.
- Valve Corporation. (2025, July 5). Finn Dorset's Institute For Livestock Replication on Steam. Steam Store.
- Valve Corporation. (2025, August 19). Operation: New Earth on Steam. Steam Store.
- Valve Corporation. (2025, May 14). Galaxy Life on Steam. Steam Store.
- Valve Corporation. (2025, August 19). Pixel Starships on Steam. Steam Store.
- Valve Corporation. (2025, August 6). Project Entropy on Steam. Steam Store.
- Valve Corporation. (2025, August 19). Star Conflict on Steam. Steam Store.
- Valve Corporation. (2025, August 18). Alien Swarm: Reactive Drop on Steam. Steam Store.
- Valve Corporation. (2025, August 19). Entropy : Zero 2 on Steam. Steam Store.