Beyond All Reason. It’s an rts game I’ve been playing recently and is fairly good. Focus more in large scale spectacle of 8v8 multi-player than micro balance.

It is also free and open source

StarSector (whoops, not two words) https://fractalsoftworks.com/

Awesome game

Voices of the Void on Itch.io. it’s sort of like xfiles: the rpg. you live in a satellite field and you use old equipment to track suspicious signals from space and sell them off for upgrades and supply money. Things… happen. while you’re carrying out this peaceful existence. suspicious, freaky things. 🛸

it’s been out for a couple years now and it’s very far in development but they are saving the steam listing for a more full release.

edit: go into this game blind

Minecraft java edition, but that feels like cheating

There are a lot of cool free games playable on your browser made for game jams on itch.io

Old school RuneScape

Shattered Pixel Dungeon - roguelike

Luanti (previously known as Minetest) - voxel builder

lichess - chess

Guild Wars 2

It normally is not a steam game. You can buy it through steam if you want, but you can buy it straight through the maker of the game. just search for Guild wars two on Google. That will show you the actual homepage for the game.

I haven’t played it in a long time, but I always enjoyed Super Tux Kart. It reminded me more of the Moorhuhn / Crazy Chicken Kart games than Mario Kart. In general, before Steam Proton made Gaming on Linux almost free of any hassle, I spent more time with free and open source games like Nethack or Battle for Wesnoth that are available in many Linux package managers.

The Operative: No One Lives Forever

Beyond All Reason. Outstanding RTS thats independant and free. Not F2P but actually free.

Wargus

DevilutionX

Doom2

ScummVM

OpenMW

Daggerfall Unity

UnCiv

Toby Tobu girl!!

https://tangramgames.itch.io/tobu-tobu-girl-deluxe

Also pico 8 games.

And https://www.wesnoth.org/

There’s MUDs like Carrion Fields and Lost Souls.