Backed Up.
Favorite.

That's all.

-In Progress
-Next Up
I might combine these into 'Installed'

-Completed

and then just types of games

-Rogue/Quick (as in play for a bit)
-TBS/RPG
-Story/Build
-Action/Adventure

and within my hidden games I have some marked as 'Gift It' for games that people may want.

None. I can't be bothered to tag my oodles of games.

I use an offline database which is fully owned and controlled by me, and has unlimited tagging, sorting etc. And no third party control.

Neat.

Anyway, the size of my GOG collection doesn't justify the use of tags.

Only "Completed".

But I'm thinking about adding "hot seat" and "split/same screen", since those features are not present as searching criteria. And I like to play from time to time with my siblings in one of those games with hot seat/split screen.

I use 3:

Completed: Pretty obvious what this one is for, I think.

Delete: Games I would delete from my account if I could. Mostly games I picked up when they were free that I have no interest in actually playing, but took them just because they were free, and also for games I didn't want that were bundled with ones I did, i.e. King's Quest 8.

Unsure: Games I've picked up for free that weren't on my radar before, but look interesting enough to not automatically get a delete tag, e.g. Fantasy General. and Contructor Classic 1997.

Both Delete and Unsure games are hidden.

early access
essential games
not played
played - good game
played - did not work
played - needs controller
played - may play again
played - not likely to play again
played - not interested
played - crap

Will Play Again
Won't Play Again
Beat

- now playing
- next to play [among the default ones, used on a couple of games initially, now unused]
- installed [but not currently playing, may or may not be paired with started, as the case may be]
- started [but not currently playing, may or may not be paired with installed, as the case may be]
- backlog [intend to eventually play, but never started nor currently installed]
- uncertain [whether I ever intend to try to play or not]
- not interested
- abandoned
- completed
- favorite [think it's left over from default ones, unused]

Listed them in order too, and I sort by tags order. Not interested, abandoned and completed are all hidden.

- Completed
- Played
- Kids
- Relax

Chiefly, two really nondescript tags.

One is along the lines of:
-"Shiny New Thing/Unboxed/Un-played"

The second one hovers around:
-"Had my fun/Enjoyed/Completed"

For everything else, I go by some level of intuitive memory of what I've decided or wanted. Perhaps when my library balloons to a vaster amount, more will pop out of the either. *^_^*