Look at anything from publisher New Blood Interactive on Steam for a starting point. Mostly retro style FPS from differing eras, but there are a few other game types. Plus you'll struggle to find any that don't have thousands of user ratings in either very positive or overwhelmingly positive brackets.

Gloomwood (first person stealth) and Fallen Aces are a couple of gems still in early access.

A lot of fun old AAA games run on potatoes. And there's so many of them that you won't have issues finding something new to you.

The majority of my indie titles run on a potato.

> I look forward to an eventual return to fun video games

They weren't saying they wanted games that run on old hardware. It's just the trope of "back then hardware was bad and games were good. Now hardware is good and games are bad."