Thanks, but I think the information we really need from GOG staff at this point isn´t whether the feature is new, but:

1. How exactly does the warning system work? (I have my birthdate set in my account but when using Galaxy, I get the warning every time I click on a game, not just once per session)

2. Will this be all or is GOG planning to implement further age verification systems / blocks?

Here´s some educated guesses for my fellow GOG users as to what´s going on: As far as I can tell, the warning comes up depending on the age rating a game has in the GOG catalogue (which might be different from country to country). For example, I get mature content warnings for the Overlord games, both of which have USK ratings (German ratings board) of 16+ shown on the store page. I don´t get a warning for Graven, presumably because that game has no USK rating on the store page yet, as it is in development.

This might even be preparation for including an automated process in line with the IARC system. For those who don´t know: For a couple of years now, there has been an international effort to create an automated age rating system ("International Age Rating Coalition") where game developers can fill out a questionnaire and get a sort of preliminary age rating, depending on the laws of the country they want to publish their game in. That way, devs can release their games with an age rating even if they haven´t had their games reviewed by the respective organisations (like USK, PEGI etc.) yet. As far as I am aware, some countries already have legislation which requires games stores to implement this system - and yes, Germany is one of these (new "Medienstaatsvertrag" introduced some months ago), but I think other countries in the EU are also planning to create such legislation.