Well, I mean that you can technically play the game. You can register, log in, walk around, pick up items, drop items, wear items, wield items, practice, train, fight, die, cast spells, use skills, do socials, check your stats, check your score, check your inventory, open/close/lock/pick doors, join groups, chat, send notes, etc, etc.
You're right that it's never really done, but my theoretical goal is basically a bare-bones MUD written in Go that anyone else could pick up and turn into a fully featured one. More practically, I'll probably just make a couple dozen areas and stick it on a server and see if anyone wants to play before I spend too much more time on it.