[simscitizen]

I'm not sure if this works well for more demanding games, but recently I wanted to let my kid play Number Munchers and Oregon Trail and just built a webpage for those games using js-dos. It worked well enough for those games.

[vunderba]

I've seen JS-DOS used for id software stuff like DOOM so I think it's plenty capable.

The person who created js-dos runs https://dos.zone as well which has a bunch of abandonware running on the browser.