Classic DOOM has best Linux support of all games in my opinion. Because it was opensourced and plenty of great community-maintained source ports.

Doom has tons of amazing community-made content (WADs) made within last 30 years. Like what other games have mods that feature whole original soundtracks? It also has pretty competitive speedrunning and multiplayer scene.

So to play the game you need iwad file containing levels and resources which are unfortunately not free. So your options are

1. Buy D1+D2 on steam/gog, grab the iwads, ignore official source port and go play much better community ones
2. Pirate it. Extremely easy, the iwads didn’t change since the 90s and have been shared all over internet.
3. Use the community-made iwad from freedoom project. These are completely free. I started playing DOOM with freedoom :)