Thank you. I know of it, my idea is to add a shortcut to quickly add a tag like "finished", same way we can configure one to add a game to Favorites. So I can show a proper badge on each game.
That is exactly what I'd love to do, but right now it can't be done, since you can't add tags "from code". In my theme if a user adds a tag "Completed" then the badge appears, but you have to explain the user that he has to do it that way.
The other issue of this is that tag names must be entered using a "real" keyboard, I was planning to go "keyboard free" for people using cabinets and provide an on-screen keyboard to enter text (I already use a spinoff of the keyboard search plugin for search strings), but it won't work for tags sadly. Or let the user connect the keyboard, define a list of useful tags, and then the layout could show the list to select from. This can't be done either for the same reason.