Drm on Steam is optional. It’s up to the dev whether to include any or not.

However, if the game uses any steam features, like achievements, voice chat, leaderboards, etc., then those won’t work without steam.

If you’re looking to try something a little different, I recommend Guix.

It’s based around a nyx-style package manager written in scheme, which is also called guix. There’s an EDSL for writing package definitions. One interesting result about this is that the package manager has a REPL and a dedicated emacs mode

Instead of systemd, the PID1 process is called GNU Shepherd, and is also written in scheme.

Guix also has a strong emphasis on bootstrapping. You can build almost the entire system from source, relying on only a few binaries to start with.

I hate FPS games. They’re probably my least favorite genre. I really enjoyed HL2.

Although, I was playing through the series to get ready for Alyx, so that may have colored my perception.