The Universe session

The Universe session is an entry on your login screen, next to GNOME or Plasma. Log in to it and Universe Big Screen takes the whole screen, with no desktop behind it, the way SteamOS runs Steam in Game Mode. It needs gamescope.

Adding it to the login screen

The Arch and Fedora packages and the installer add it. On NixOS, set programs.universe.session.enable. Then pick Universe in your login screen’s session menu.

To boot straight into it on NixOS, make it the default session and log in automatically:

programs.universe.enable = true;
programs.universe.session.enable = true;
services.displayManager.defaultSession = "universe";
services.displayManager.autoLogin.user = "alice"; # your user name

Inside the session

It’s the Universe Big Screen you know, HOME and the dock over a game included. The power menu (hold B) starts with Log out, which takes you back to the login screen.

There’s no lock screen: waking the machine from suspend lands on Universe.

Settings › Network joins Wi-Fi, and Settings › Bluetooth pairs controllers and headphones. Plug your first controller in by cable, or use a keyboard, to reach those pages. A DualSense or DualShock 4 plugged in by cable pairs there and then.

Nothing in the session can ask for a password, yet gamescope, MangoHud and gpu-screen-recorder still install from Settings › Emulators & Proton › Tools. Where your system can’t install one that way, the row shows what to do.

When it can’t start

The login screen comes back when gamescope is missing or fails to start, or when Universe keeps crashing. Log in to a desktop session and open Settings › System check to see why.

In the Switch 2 and PS5 looks, the power menu says Log Out.