I've reviewed a few games I played elsewhere before I played the GOG version. I don't think there's anything wrong with that really. Yes maybe sometimes people are reviewing based on 20 year old memories which is bad, but it would be hard to tell on that alone.

How the hell can you show if games can be played without telemetry?

DAMN!!! you got point. I totally forgot.

Aside from the fact you've probably already figured out it won't work at all for offline installers, the truth is it also regularly doesn't really work well for Steam either. The number of times I've read a snarky comment on a Steam review like "But you've only played this 5 minutes!" in response to a review where the person obviously has a great deal of knowledge about the game but was running in offline mode shows that even many people on Steam can't wrap their head around how unreliable it is. The reverse is also true - anyone can fake 40hrs "gameplay" in any game just by starting it on a Friday evening and leaving it idling on the main menu in the background over the weekend. What's being "counted" isn't play-time at all but merely .exe run-time.

The only truly reliable game time tracking is internal, ie, games like Dragon Age Origins or Stardew Valley with "hours played" actually recorded by the game itself into the save fie. But even then deleting that save file and starting fresh will reset the counter. For older games it makes even less sense where someone could have something like "Doom 2, 5hrs played" on their GOG / Steam profile after recently re-buying it on GOG but literally thousands of hours of game play on the disc version they also own and have been playing for 28 years, what counts most really in terms of experience / knowledge of the game?... True but this is highly variable and works both ways. Eg, there are some games here that are very clunky without any "nostalgia hook / muscle memory" of originally awkward controls that newcomers to the game will find off-putting and "nostalgia scores" somewhat inflated. The reverse is also true though. A brand new "verified" review from someone complaining about how clunky Doom's controls are for running the original .exe in DOSBox isn't particularly helpful either when many people will be running it via GZDoom with far better controls that neither GOG nor Steam package it like. And the WAD files are identical for all platforms going back to 28 year old discs.

Likewise, what do we do with early GOG reviews like "cutscenes don't work, game doesn't work" on early reviews of Thief here on GOG that were made long before they started integrating the community TFix patch that fixed all the issues? The difference between the GOG version without it vs the newer GOG version with it is far greater than the new GOG version + TFix vs an old disc version running the same TFix. It's often people with 20 years of of experience of a game that know the most about this stuff or where to find widescreen / unofficial patches / source ports that GOG haven't included that create the most helpful reviews than someone who just bought the game blind and hasn't a clue about this stuff, regardless of which store it was bought from.

An easy fix: the user can enter the value themselves, estimating how long they've played the game (on GOG or elsewhere).

Naturally, some people might lie or exaggerate with the number, so for them there would also be a selection below the number:

"Am I telling the truth above? Yes/No/Maybe"

Or they could add an option on your review ( a box to tick ) to allow your Galaxy playtime to be shown or otherwise like Timppu said let you enter it manually if you played without the launcher.

But I understand your idea, if you go to other platforms like Steam, you can see people calling a game either a "masterpiece" or "the worst piece of crap" even though they only played the tutorial and if their playtime wasn't displayed you could have easily taken what they said into consideration before purchasing.

Sadly years later we're still waiting for an option to edit reviews so I would say they're unlikely to update the review system anytime soon.

Played time means absolutely nothing and shouldn't be used at all. Anyone can run a game and go AFK to rack up hours.

yep
just like kda in team based pvp games

Play time is so easily faked (both ways) it's worthless for reviews, obviously inaccurate for any older game that predates the tool "measuring" it (even just within the GOG store, GOG has existed since 2008 but Galaxy didn't even exist until 2014 so there's 6 years of missing time even for "verified owners"...), and useless for offline gaming. Manually adding your own times will just result in a mix of random guesses and most people leaving it blank (for the same reason they disable their Galaxy profile in the first place) whilst others develop an unhealthy expectation that everyone should fill it in so they can do the Steam thing of judging reviews on bad metrics.

As for review quality, "verified owner" doesn't mean much. Example - The Longest Journey. "Might be a great game, if it worked" says one 1* review. "Doesn't work under W10" says another. "Crashes" said another. Meanwhile, an "unverified owner" (someone who owns the game but not the GOG version specifically) like myself could easily leave a review containing a step by step guide on how to add ResidualVM to cure the "crash after cutscene" problem the others are complaining about and even add HD textures (identical for disc & GOG, just as ScummVM is), and apparently the "1* dis sux. unplayable. verified owner" will be deemed the more "authoritative" or "helpful" ones? LOL.

From my over 800 games on Steam, I only found one game that doesn't get picked up by Steam when running (Knightshift). So where does this 'regularly doesn't really work' come from?

Also, when I look at the Steam hours I've used on playing e.g. Team Fortress 2, I get depressed thinking what I could have done with all those countless wasted hours instead:

- cure cancer
- travel to the moon and back, twice!
- run for precidency

and lots of other things.

Then again, playing Team Fortress 2 is much more fun than any of those other activities I listed, so there's that.

For anyone who mostly uses Steam offline. Or for DRM-Free games on this list, with no client running at all. Or any game which is installed one way (eg, DOSBox) but run another post-install (eg, GZDoom, Quakespasm, etc). Or the many people who said in reviews "This isn't my actual game time, I started it then got called away and left it running in the background for a few hours". Or the "3hrs played" of the newest buggy AAA which were nearly all troubleshooting and not actual play. Or anyone who also owns the game elsewhere (GOG, on disc, etc) in addition to a Steam version for which total game-time will be split across platforms. Or anyone who bought a Steam version but then cracked the DRM (and need for a game-time measuring client out of it). Or...

The point is, it's hardly some indicator of review quality / user experience of a game by any means (even at the times when it is accurate).

If you need a way to track your playtime In video games, there is a application called procrastitracker. I use it for tracking and monitoring app and video game usage that doesn't have a launcher. It helps me stay on track and shows me where my time is spent.

I dunno, seeing a negative review with a one liner and 0,2 hours played tells you quite alot about the low rating.
But I agree, The total hours played are often not true to the actual time played. Even ingame timers are not that accurate, if the game allows save scumming. I can remember playing some games where I spent one hour getting the best result with the least resources used and the end of mission stats tell me 20 minutes of actual game time.
Running your own timer is probably the best way to gauge your true time spent with a game.