Free Aliens Games on Steam
Steam currently has 3,159 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 1/12/2026.
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 3,801 reviews on Steam. This breaks down to a total of 3,529 positive reviews and 272 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 179,268 reviews on Steam. This breaks down to a total of 124,468 positive reviews and 54,800 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. Trimps
A text-based incremental idle game with a ridiculous amount of unique content. Automate old stuff as you unlock new stuff to keep things interesting for hours and hours, no spam clicking necessary! Trimps is everything you love about your favorite games, distilled to their purest form.
Trimps has achieved a Player Score of 86, placing it in the #3 spot for the best free Aliens games. Its score was calculated by analyzing a total of 1,389 reviews on Steam. This breaks down to a total of 1,263 positive reviews and 126 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 Trimps on the Steam Deck.
| Release Date | 5/2/2022 |
| Developer | Greensatellite |
| Publisher | Greensatellite |
| Steam App Id | 1877960 |
4. Dungeon Crusher: Soul Hunters
A social multiplayer incremental idle rpg with clans, PvP arenas, a wonderful 3d fantasy world with a story/missions and much more.
Dungeon Crusher: Soul Hunters has achieved a Player Score of 66, placing it in the #4 spot for the best free Aliens games. Its score was calculated by analyzing a total of 374 reviews on Steam. This breaks down to a total of 261 positive reviews and 113 negative reviews — making it "Mixed" on Steam.
It can be played and ran on both Windows and Mac systems. Valve has also verified it as playable on the Steam Deck and will run well.
| Release Date | 10/30/2024 |
| Developer | Towards Mars Limited |
| Publisher | Towards Mars Limited |
| Steam App Id | 842980 |
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 8,313 reviews on Steam. This breaks down to a total of 7,612 positive reviews and 701 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. 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 #6 spot for the best free Aliens games. Its score was calculated by analyzing a total of 808 reviews on Steam. This breaks down to a total of 489 positive reviews and 319 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 |
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 53, placing it in the #7 spot for the best free Aliens games. Its score was calculated by analyzing a total of 197 reviews on Steam. This breaks down to a total of 107 positive reviews and 90 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. 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 72, placing it in the #8 spot for the best free Aliens games. Its score was calculated by analyzing a total of 2,877 reviews on Steam. This breaks down to a total of 2,120 positive reviews and 757 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.
9. 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 #9 spot for the best free Aliens games. Its score was calculated by analyzing a total of 30,568 reviews on Steam. This breaks down to a total of 30,048 positive reviews and 520 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).
10. 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 #10 spot for the best free Aliens games. Its score was calculated by analyzing a total of 23,306 reviews on Steam. This breaks down to a total of 22,126 positive reviews and 1,180 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 |
More Free Aliens Games
Explore even more rankings for the 100 best free Aliens games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 4,163 | 7/27/2023 | 89 | Free | Steam Charts | |
| 836 | 11/15/2021 | 69 | Free | Steam Charts | |
| 605 | 5/2/2022 | 86 | Free | Steam Charts | |
| 305 | 10/30/2024 | 66 | Free | Steam Charts | |
| 301 | 8/31/2022 | 89 | Free | Steam Charts | |
| 197 | 12/14/2016 | 59 | Free | Steam Charts | |
| 178 | 4/17/2024 | 53 | Free | Steam Charts | |
| 148 | 5/23/2023 | 72 | Free | Steam Charts | |
| 127 | 8/20/2022 | 96 | Free | Steam Charts | |
| 105 | 4/20/2017 | 93 | Free | Steam Charts | |
 | 98 | 12/15/2022 | 88 | Free | Steam Charts | |
 | 91 | 10/2/2024 | 81 | Free | Steam Charts | |
 | 88 | 12/3/2025 | 31 | Free | Steam Charts | |
 | 74 | 2/27/2013 | 71 | Free | Steam Charts | |
 | 53 | 12/5/2014 | 90 | Free | Steam Charts | |
 | 44 | 3/27/2015 | 91 | Free | Steam Charts | |
 | 26 | 9/16/2022 | 95 | Free | Steam Charts | |
 | 25 | 9/11/2025 | 63 | Free | Steam Charts | |
 | 23 | 7/28/2025 | 60 | Free | Steam Charts | |
 | 20 | 10/21/2025 | 86 | 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. (2026, January 12). Steam Store. Steam Store.
- Valve Corporation. (2026, January 12). Unnamed Space Idle on Steam. Steam Store.
- Valve Corporation. (2026, January 13). Halo Infinite on Steam. Steam Store.
- Valve Corporation. (2025, December 26). Trimps on Steam. Steam Store.
- Valve Corporation. (2026, January 15). Dungeon Crusher: Soul Hunters on Steam. Steam Store.
- Valve Corporation. (2025, September 30). Galaxy Life on Steam. Steam Store.
- Valve Corporation. (2026, January 9). Operation: New Earth on Steam. Steam Store.
- Valve Corporation. (2025, December 26). Project Entropy on Steam. Steam Store.
- Valve Corporation. (2026, January 16). Pixel Starships on Steam. Steam Store.
- Valve Corporation. (2026, January 13). Entropy : Zero 2 on Steam. Steam Store.
- Valve Corporation. (2026, January 15). Alien Swarm: Reactive Drop on Steam. Steam Store.