01 / Pandemic Mode
Make the outbreak your own.
Pick enemy types, resources, difficulty, and infected strength. Build the kind of run you want, from slow survival to full horde chaos.
Early Access / Open-World RTS / Military Survival
Command CERC Hunt Patient 0
Cepheus Protocol is an open-world RTS where you fight the Pangu Virus across the Bay Area, evacuate civilians when you can, and take direct control of Operators when the line breaks.
Directive
Cepheus Protocol Enacted
Authority
CERC
Outbreak
Pangu Virus
Primary Target
Patient 0
What Makes It Different
Your outbreak, your rules.
Cepheus Protocol is an open-world RTS with co-op, infected hordes, third-person Operator control, civilian reputation, and sandbox rules that let you make the outbreak as brutal or manageable as you want.
02 / Civilian Evacuation
Save them, or risk feeding the swarm.
Evacuation pulls civilians out of Chelsey's reach and cuts into her biomass. It also means staffing evac zones, defending bigger targets, and dealing with reputation when camps get messy.
03 / Operator Control
Sometimes you go hands-on.
Operators are customizable hero units. Tune their weapons and abilities, take direct control in third person, and use them to turn a breach, convoy, or last stand before it collapses.
04 / 16-Player Co-op
Split the operation across real players.
Coordinate roles, divide fronts, and keep the quarantine alive when multiple failures are happening at once.
05 / Living Infection
The Infection Adapts.
Patient 0, lieutenants, special mutations, and the infected swarm keep forcing your plan to change as the days get worse.
06 / Consequences
Be their savior, or the enemy of the people.
Evacuating people can earn trust and income. Killing or abusing civilians can tank your reputation and bring militias to your doorstep.
CERC HQ
Your one-stop shop for all things Cepheus Protocol.
Welcome to Cepheus Protocol HQ, your ultimate weekly briefing on all things Cepheus Protocol!
Join the Halcyon Winds team as we explore the latest updates, reveal behind-the-scenes development stories, and answer community questions about the game.
From exciting new features to design challenges, this is your all-access pass to the evolving world of Cepheus Protocol. Tune in every week and stay ahead of the outbreak!
Open CERC HQ on News
Early Access Roadmap
Track the 2026 roadmap.
See what is already live, what the team is fixing now, and what is coming later in 2026.