Didn’t see this was free games community, sorry!

I haven’t validated that these have low enough requirements, but they are very not-demanding games in my experience. You can also use Proton to run them on linux if they don’t have a native version.

Baba is You - simplistic graphically, but immensely satisfying mechanically. Amazing puzzle game.

Celeste - gorgeous graphics and buttery smooth controls, a platformer that is encouraging and supportive all the way through but ranges from “easy as pie” to “hard as nails” as you progress. One of the most satisfying games to complete every level for. One of the best soundtracks ever. Trans rights!

Fez - another simple-ish at face value platformer game, but this time with puzzles as the main thread instead of action. Super satisfying puzzles and an amazing soundtrack.

Omori - an RPG which eventually deals with some heavy subject matter but does so tastefully and maturely. It’s a splendid story either way you spin it, and lots of fun.

Undertale - same as above, but shorter and more “punchy”. One of the best soundtracks in gaming, and a cast of characters you’ll come to feel like your family. It’s quite subversive for the genre, so it’s a fun experience. It has an episodic sister game which is still in the works.

Void Stranger - a block-pushing styled game, but incredibly subversive for the genre. Gorgeous visuals, great soundtrack, and some truly mindbending puzzles. It gets super hard, but it’s also super satisfying to beat.

Stardew Valley - cozy farming game, really just oozing passion and love from the developer(s). Lots to do, many unique people to meet and things to see. Pretty graphics and stunning soundtrack. Fall in love with an NPC, marry them if you want. Or don’t do any of that. Make your own fun in this one, there’s a bunch of aspects to get into.

Citizen Sleeper - perhaps on the edge of games I’d recommend, performance wise, but absolutely a must-play. A gripping, beautiful sci-fi story, told in a tabletop RPG style. You won’t be able to help falling in love with the rag-tag character cast, and shedding a few tears along the way. It’s very down to earth but makes me long for the stars at the same time.