PCGame

Cepheus Protocol

Open-world military strategy against a spreading zombie outbreak

Halcyon Winds · Released May 15, 2020 · Early Access

ActionAdventureIndieMassively MultiplayerRPGSimulationStrategy

Reviews
Mostly Positive
76% of 3,179
Recent reviews
Mixed
50% of 42 in 30 days
Players
62
daily peak, Nov 7, 2026
Steam Deck
Playable
Last update on Steam
2 months ago
Sep 4, 2026
Minimum PC
1060 GTX
8 GB RAM · 8 GB disk
Full requirements

What is Cepheus Protocol?

Cepheus Protocol is an open-world, real-time strategy game set in the Bay Area during a virus outbreak that turns people into infected swarms. You command military units, build defenses, and try to contain the spread. You can also control an operator from a third-person view, adjust Pandemic Mode settings, or share command in co-op.

For you if...

  • +you like directing soldiers against growing infected hordes
  • +you enjoy coordinating tactics with other players
  • +you like adjusting the rules of survival scenarios

Not for you if...

  • −you prefer turn-based combat to real-time unit management
  • −you want a finished game rather than early access

What players say

76% of 3,179 reviews are positive · 50% of 42 in the last 30 days

Players praise the military-versus-infected premise and cooperative play. They frequently complain about unit pathfinding and bugs, and many say the ongoing rebuild lacks parts of the older version.

Players over time

▲ +3% vs a month ago

Players online on Steam, one sample a day.

Highest since Sep 2026: 95 players on Oct 25, 2026.

Show the data
DayPlayers
Nov 7, 202662
Nov 6, 202655
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Nov 4, 202653
Nov 3, 202638
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Nov 1, 202652
Oct 31, 202656
Oct 30, 202654
Oct 29, 202663
Oct 28, 202665
Oct 27, 202680
Oct 26, 202684
Oct 25, 202695
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Oct 23, 202679
Oct 22, 202681
Oct 21, 202667
Oct 20, 202644
Oct 18, 202671
Oct 17, 202648
Oct 16, 202632
Oct 15, 202633
Oct 14, 202646
Oct 13, 202656
Oct 11, 202647
Oct 10, 202653
Oct 9, 202659
Oct 8, 202668
Oct 7, 202643
Oct 6, 202656
Oct 4, 202658
Oct 3, 202639
Oct 2, 202640
Oct 1, 202631
Sep 30, 202641
Sep 29, 202639
Sep 27, 202645
Sep 26, 202638
Sep 25, 202630
Sep 24, 202629
Sep 23, 202621
Sep 23, 202634
Sep 22, 202641

Screenshots and trailer

Cepheus Protocol screenshot 1

Cepheus Protocol system requirements

Minimum: 1060 GTX, 8 GB RAM, 8 GB of disk space.

As published by the developer.

Can my PC run Cepheus Protocol?

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Minimum

OS
Windows 10/11 (64-bit)
Processor
Intel® Core™ i5-4500K
Graphics
NVIDIA GeForce 1060 GTX or AMD Radeon Equivalent 4 GB
Memory
8 GB RAM
Storage
8 GB available space
DirectX
Version 12
Notes
**recommended SSD install for optimal performance

Recommended

OS
Windows 10/11 (64-bit)
Processor
Intel® Core™ i7-6770K / AMD Ryzen 5 1500X
Graphics
NVIDIA GeForce 2060 GTX or AMD Radeon Equivalent 6GB VRAM
Memory
16 GB RAM
Storage
8 GB available space
DirectX
Version 12
Notes
**recommended SSD install for optimal performance

Does Cepheus Protocol have co-op or multiplayer?

Yes: co-op online; MMO. It also has a single-player mode. With Remote Play Together, one copy is enough to play the local modes online with friends.

Does Cepheus Protocol run on Steam Deck?

Playable Playable: it runs on Steam Deck with some adjustments.

  • Default controller config not fully functional
  • Sometimes shows mouse, keyboard or non-Deck controller icons
  • Some text entry requires manually opening the on-screen keyboard
  • Some in-game text is small and may be hard to read
  • Default configuration is not performant

PC version details

DRM
None declared on Steam
Controller
Keyboard and mouse
Platforms
Windows
Achievements
5
Steam features
Workshop, Cloud saves, Family Sharing, Trading cards
Languages
Full audio: English. Text only: Simplified Chinese, Korean, German, Japanese, Russian, Spanish - Spain, Portuguese - Portugal, French.

Does Cepheus Protocol use AI-generated content?

No AI-generated content is disclosed on the game's Steam page.

Self-reported by the developer under Steam rules: it covers AI content that ships in the game, not tools used to make it. Steam page checked on Nov 7, 2026. How to filter AI games on Steam

Tags

Recent updates

7 DLC available.

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