I'd really love to see a similar approach but applied to games much older, like the ones you have to pull out a DOSBOX to play, or a Win95 virtual machine. The Win95 games are going to be much more difficult to set up because the VM needs a bunch of stuffs to work properly (sound, video) while the DOSBOX does everything for you.
Blog post author here. Yes, I'm planning to do this for much older games in the future, and you're also right that DOSBox does a lot of that for you! One thing I've noticed is websites that let you play using old DOS games via DOSBox right from your browser (e.g., see https://www.dosgames.com/ ), so I was going to make a blog post for how to do that yourself, from scratch. Would that be of interest?
BTW is there some way to perform save/load functionality without log-in? Maybe we can use cookies to identify users? Just a thought as I'm not a programmer...