So, here is the problem. Checked Witcher 3 GOTY and BIT.TRIP RUNNER - both are new games, both 0h 0m. As i can notice, in non-GOTY WItcher 3 is also doesn't work, i'm not sure - 201h 20m, as it was 6 month ago, as i remember.
Tried to reinstall games, reinstall Galaxy, to change language in Galaxy and Witcher 3 - NOTHING.
Can't say anything about achievments, maybe they don't work too.

Do you mean that the the playtime for your regular Witcher 3 has disappeared?

Have you tried restarting Galaxy? I’ve heard that, sometimes, playtimes get blank but fix themselves after a restart. (Playtimes should never completely vanish, even after a new install.)

Not exactly. Time doesn't count at all. It was 0m in W3 GOTY edition - it's still 0m. BIT.TRIP RUNNER, also a new game: was 0m - still 0m. Witcher 3 non-GOTY: was 201h 20m - still 201h 20m.
Yeah, i've tried to restart Galaxy - nothing.

Oh. In that case, I don’t really know what could be the cause. Were you playing offline? (Time‐tracking only works if Galaxy is online the moment you close the game.)

As i can understand, i play online. Well, i hope it's temporary GOG servers problem or something like this.

I also had that problem with some other games. Don't know how to solve it.

I freaking love statistics in any form.
And finally - if something doesn't work, it's strange and should be resolved.

I have no idea, then. You should try posting in the official Galaxy thread, though. It will have more visibility to the specialised guys, and you’ll have more chance of getting an answer from the developers.

It is more a problem of the still in beta galaxy client. The time tracking has been buggy for a long time. Sometimes it works, sometimes not. At least I never saw it working completely correctly *shrug*

I never played in gog day by day and actually had problems with it only in may-july 2015. Well, it happened again [sigh]. Will post to oficial Galaxy thread, maybe i'll give some more replies about it.

To me it only counts time if I actually launch the game within Galaxy, if I launch it from the desktop shortcut it won't count it no matter if Galaxy is online or not.

If it doesn't count when opening the game within Galaxy itself when it's online, then I have no idea.

My Gwent playtime count got stuck at 38 minutes, never changes even if I only launch it from Galaxy.

Currently game time tracking works for me only maybe once in twenty times when launching a game. Usually the game starts and the button in Galaxy goes green again after a second (meaning Galaxy has "lost the grip" on the game.

This is normal for some games which use launcher that start the actual game and then end themselves. But currently this happens with every game. And sometimes (rarely) it works again. Strange...

So I also had this problem with my Witcher 3. I know it's late, but I got my solution, hope I can help.

It worked fine first, even after I reinstalled Windows and imported game files. But after recently I reinstalled Windows again, installed Galaxy, and imported game files, the timer and achievement went broken. - I mean not updating at all.

I notice after I exit in the game, in Galaxy, the Play button is still remained gray, and "The Witcher 3" process in Task Manager is still there. Sometimes it's just 700MB-ish or 2GB or 0KB even. End that process, Galaxy continues to upload cloud save and then activate play button, update playtime.

I changed the Witcher .exe file in game folder to run as an administrator, and it works like before, no problem at all.
- right click "[The Witcher 3 Wild Hunt]\bin\x64\witcher3.exe" - Properties - [Compatibility] - Check Run this program as an administrator.