The Rebuild Is Now the Main Game (Build Switch Update)

TLDR

• The Rebuild is now the standard installed version of Cepheus Protocol.

• The old version is now called Legacy, and it remains available as a Beta option.

• This rebuild was done to restore stability, improve performance, and modernize the foundation so the game can scale again.

• That same foundation also allows co-op to exist from the start, instead of being bolted on later.

• We are targeting end of Q1 2026 to bring back the remaining missing pillars, rebuilt and improved.

Which Build Should You Play?

• Default (Standard Install) This is now the rebuilt version of Cepheus Protocol and the main version we maintain going forward. Play this for the current supported game, best performance, and all new updates.

• Experimental (Beta Branch) This is the testing branch ahead of Default, where upcoming features land first. Expect bugs, frequent updates, and possible save issues. Opt-in only if you want to help test new changes early.

• Legacy (Original) (Beta Branch) This is the preserved prebuild version for older saves and the original gameplay foundation. Opt into this if you want to continue old saves or stay on the classic build. This branch will not receive future updates. You can see the "foundation" that we based the rebuild on for the newly merged into "default" here.

• Legacy (Pre Merge) (Beta Branch) This is the last version from before the rebuild became Default. If you were playing the rebuild while it was still a Beta branch.

The Big Change

Going forward, when you install Cepheus Protocol, you are installing the rebuilt version.

For most of the last year, the rebuilt version existed as an opt in Beta branch while we validated the foundation in public tests. A lot of players never saw that Beta branch, which caused real confusion about what version was being worked on and why certain things felt inconsistent.

So we are ending that confusion. The game is alive as ever and is still passionately worked on a daily basis by our team. We have been biding our time developing the rebuild on public/private betas slowly ticking away at the core mechanics missed from the rebuild readding them as we go. We now feel the current state of the game is enough to flip the builds.

Going into next week we will be shipping Doctrines and start the save system. We expect to have an early doctrines to show by Friday and have it in UI wise by mid next week. We will update as we progress here and on our discord.

A quick Catch up!

[dynamiclink href="https://steamcommunity.com/games/979640/announcements/detail/537736957039477253"][dynamiclink href="https://steamcommunity.com/games/979640/announcements/detail/537735054151909378"]A few notable changes recently:

• Infected Military, Police and Swat will now roam the island with higher stats then standard infected. They start showing up early and increase in numbers as the days go on!

• Infantry Gates

New Infected Variants replace legacy models

[dynamiclink href="https://youtu.be/FlKfVGDYkPM"]

• 16 Player Coop RTS/TPS hybrid gameplay!

• Firing Computer from the MLRS ported to the Cerberus Mortar with the rebuild

[dynamiclink href="https://youtu.be/BzcmJ-hsIeI"]

Legacy Version

Legacy remains available as a preserved snapshot of the pre rebuild version.

If you want to keep playing that older snapshot, or if you want to keep older saves, you can do that through Steam Betas.

What This Rebuild Actually Was

This was not a content patch. It was a full foundation revamp.

We rebuilt the core systems so the game can scale properly again, run better, and stop breaking under the weight of legacy technical debt. That benefits everything:

• Single player flow and stability

• AI behavior and consistency

• Vehicle systems