Get Nucleus Co-op
One download, no installer, no account. Unzip it, start it, and your PC is a couch co-op console.
Install in four steps
Pick a folder
Create
C:\NucleusCo-op, or the same at the root of the drive your games are on. Not in Program Files, OneDrive or your user folder.Allow it in your antivirus
Add the folder to your antivirus exclusions before extracting: some files that hook into games are often flagged by mistake.
Unzip
Right-click the zip, Properties, tick Unblock, then extract it into the folder, ideally with 7-Zip.
Play
Start
NucleusCoop.exe, add your games and hand out the controllers.
The full install guide covers SmartScreen, updates and where everything goes.
Then
Nucleus Co-op 2.4.2
NucleusApp.zip, 97 MB. Free for Windows 10 and 11, 64-bit, under the GPL-3.0.
Download for WindowsNucleus Co-op 3.0 is in beta. Nucleus Co-op 3, with the new couch-friendly interface, is in beta. These guides already describe it; the steps are the same in 2.4, the screens look different.
- Windows 10 or 11, 64-bit
- .NET Framework 4.7.2, Visual C++ 2015-2022 (x86 and x64): Nucleus offers what's missing
- The game installed once, from Steam or another store
- One controller, or keyboard and mouse, per player
System requirementsOnly download from this page or the official GitHub releases.