Free Aliens Games on Steam
Steam currently has 3,210 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 2/1/2026.
Looking for more? Explore other lists such as:
- Best aliens games on Steam
- Best aliens Steam Deck games
- Best aliens Steam games for Mac OS
- Best aliens Linux games on Steam
- Free Steam games
- Most played Steam games
- Best rated Steam games
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 3,882 reviews on Steam. This breaks down to a total of 3,608 positive reviews and 274 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 179,454 reviews on Steam. This breaks down to a total of 124,564 positive reviews and 54,890 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. 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 67, placing it in the #3 spot for the best free Aliens games. Its score was calculated by analyzing a total of 382 reviews on Steam. This breaks down to a total of 268 positive reviews and 114 negative reviews — making it "Mostly Positive" 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 |
4. 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 #4 spot for the best free Aliens games. Its score was calculated by analyzing a total of 1,401 reviews on Steam. This breaks down to a total of 1,273 positive reviews and 128 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 |
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 8,337 reviews on Steam. This breaks down to a total of 7,635 positive reviews and 702 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. 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 #6 spot for the best free Aliens games. Its score was calculated by analyzing a total of 23,362 reviews on Steam. This breaks down to a total of 22,175 positive reviews and 1,187 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 |
7. 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 #7 spot for the best free Aliens games. Its score was calculated by analyzing a total of 809 reviews on Steam. This breaks down to a total of 489 positive reviews and 320 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 |
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 71, placing it in the #8 spot for the best free Aliens games. Its score was calculated by analyzing a total of 2,885 reviews on Steam. This breaks down to a total of 2,122 positive reviews and 763 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. 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 #9 spot for the best free Aliens games. Its score was calculated by analyzing a total of 206 reviews on Steam. This breaks down to a total of 110 positive reviews and 96 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 |
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 30,776 reviews on Steam. This breaks down to a total of 30,257 positive reviews and 519 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 | ||||
|---|---|---|---|---|---|---|
| 4,005 | 7/27/2023 | 89 | Free | Steam Charts | |
| 1,186 | 11/15/2021 | 69 | Free | Steam Charts | |
| 1,137 | 10/30/2024 | 67 | Free | Steam Charts | |
| 678 | 5/2/2022 | 86 | Free | Steam Charts | |
| 319 | 8/31/2022 | 89 | Free | Steam Charts | |
| 255 | 4/20/2017 | 93 | Free | Steam Charts | |
| 187 | 12/14/2016 | 59 | Free | Steam Charts | |
| 146 | 5/23/2023 | 71 | Free | Steam Charts | |
| 144 | 4/17/2024 | 53 | Free | Steam Charts | |
| 111 | 8/20/2022 | 96 | Free | Steam Charts | |
 | 100 | 12/15/2022 | 88 | Free | Steam Charts | |
 | 94 | 10/3/2024 | 81 | Free | Steam Charts | |
 | 85 | 12/3/2025 | 31 | Free | Steam Charts | |
 | 59 | 2/27/2013 | 71 | Free | Steam Charts | |
 | 48 | 9/16/2022 | 95 | Free | Steam Charts | |
 | 44 | 3/27/2015 | 91 | Free | Steam Charts | |
 | 31 | 9/11/2025 | 61 | Free | Steam Charts | |
 | 27 | 12/5/2014 | 90 | Free | Steam Charts | |
 | 24 | 12/12/2023 | 73 | Free | Steam Charts | |
 | 23 | 7/28/2025 | 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. (2026, February 1). Steam Store. Steam Store.
- Valve Corporation. (2026, February 1). Unnamed Space Idle on Steam. Steam Store.
- Valve Corporation. (2026, February 10). Halo Infinite on Steam. Steam Store.
- Valve Corporation. (2026, February 2). Dungeon Crusher: Soul Hunters on Steam. Steam Store.
- Valve Corporation. (2025, December 26). Trimps on Steam. Steam Store.
- Valve Corporation. (2025, September 30). Galaxy Life on Steam. Steam Store.
- Valve Corporation. (2026, February 4). Alien Swarm: Reactive Drop on Steam. Steam Store.
- Valve Corporation. (2026, February 10). Operation: New Earth on Steam. Steam Store.
- Valve Corporation. (2026, February 13). Pixel Starships on Steam. Steam Store.
- Valve Corporation. (2026, February 8). Project Entropy on Steam. Steam Store.
- Valve Corporation. (2026, January 22). Entropy : Zero 2 on Steam. Steam Store.