Hello all,
I downloaded games directly from the GOG website (my account). If I play any of games that have achievements, then later open GOG Galaxy, will Galaxy detect any achievements? Or do I have to launch from GOG Galaxy?

Thanks! THartmann9374

Generally GOG Galaxy is able to detect offline achievements when launched, especially if the game also has in-game achievements. But not all games work like this and some achievements are unlocked only if you play live with GOG Galaxy, so I'd say that for safety it's always better to activate GOG Galaxy and launch the game through the launcher.

Obviously this also works with games installed through offline installers.

Yeah, if you hunt achievements, the best way is to use Galaxy to run your games. As any other way, can be rather problematic achievement-gathering-wise.