I see we are in the same boat. At least when it comes to number of GOG games, things that truly matter in life.

Probably something they removed from our library. There might have been a thread about it but it was some time ago.
It's just annoying.

Reading this I absolutely love my wife. She's a gamer herself and encourage me to play as much as possible, and we often either play together or by watching a play-through. At the same time - she WOULD kill me if I even touch her weekend muffin with chocolate chips...

These are the "games" I've "hidden" so far (although, I might hide more in the future):

Currently I am only aware of Demos being removed and only a small number of them, plus the odd file from a game, usually due to an update or remaster of something that was added without permission, like a soundtrack. The one I remember most right now, was when some expansions were removed from Wolfenstein 3D, but later restored.

I guess it is possible, that a game was removed while a new version added automatically to our library, as a replacement, though I have seen no indication of anything left behind. Still, I have nothing set to hide, and that might be the difference.

not here but on steam i hide the adult games from prying eyes...

I've finally caught up with UPDATES, again, and I see that while I have a notification of an update, when I click on that option it says nothing to reveal. Obviously a similar kind of glitch, as it has persisted a few days.

I can't even unhide it to see what it is.

I really wish the hide feature would also hide the update notifications for hidden games. This has been a long going problem.

There are a few wishlist entries for that:
https://www.gog.com/wishlist/site/option_to_disable_update_notifications_for_hidden_games
https://www.gog.com/wishlist/site/dont_notify_for_updates_to_hidden_games
https://www.gog.com/wishlist/site/please_stop_update_notifications_for_hidden_games_in_library
https://www.gog.com/wishlist/site/hide_updates
Few votes though, rather strangely I'd say.

Might as well add my upvotes then, thanks for sharing those!

In all likelihood a coding bug, where the count is one more than it should be.

So probably not worth worrying about.

Many of us have a discrepancy when it comes to the total count of owned games. In some store views etc, I either see one more or one less ... been that way for years, maybe ever since one of my first purchases. In fact, early on I was able to grab a Witcher 3 DLC, even though I did not own the game at that time. I can still see that listed as a separate game in my Library, even though I later bought the complete game.

So I am guessing, that sometimes GOG's software counts it as a game and at other times doesn't.

I normaly hide duplicates, for exemple, I have System Shock, that means the package comes with Classic System Shock and the Enhanced Edition, so I hide the classic one.

I hide demos and goodie packs. I also hide games which are trumped by versions I feel are improved. Prime example is blood. I have one unit and fresh supply. Crystal caves secret agent and monster bash are also examples.

Thank you, the wish has my vote. I find it perplexing why digital stores lack so many essential features for organizing and navigating goods. While I understand the strategic delays in physical stores that encourage impulse purchases, the digital landscape should be different. Online shoppers typically know what they want and are methodical. When we can't quickly find items, we tend to move on. Major platforms like Amazon, Steam, EA, all face this issue. I'm shifting the focus here to the shopping experience rather than our purchased goods (libraries) because if these titans neglect the former, where they generate revenue, there's little hope for improvement in the latter. Where is the promised digital convenience? Unbelievable.