The cover in the Galaxy games list has unrated written on it, but it installs the lagacy version. People in this forum claimed that they found a switch to enable the unrated version or that the GoG website lists an unrated offline installer.
I found neither of that in my library in Galaxy nor the site.

So how to actually install the unrated version?

I'd like to know this as well, was going to buy and install the unrated version,
but will wait for a answer to above posters question !

It seems you're from Germany and have bought Agony only. The unrated version isn't available for us.
There are ways to buy it regardless though. You can contact me via PM if you want to know more.

+++ You'll get two entries in your library (Agony & Agony UNRATED) where you can download the offline installer as usual.
If you want to install it from Galaxy you have to select the version on the game's page in Galaxy. Look at the attached Screenshot.

Yep, looks like i really only got the blurry version and like Unrated is region-locked.
Unrated is available to buy when i use an IP from the Netherlands. It also seems like you can't buy it with PayPal (maybe because of the adult content and PayPal itself still only being mature yet).
But i bought it using the least privacy friendly provider in the list (yes, it is called "sofort"). And i immediately downloaded the offline installer, so availability of the game stops dependng on an online service.
It is now visible in Galaxy without VPN too though. So the region lock seems to be buy-time only - for now...

Whoever reads this - you can skip the remainder if you just wanted to know how to buy Unrated from inside a restrictive country.

This time i did not revert to my old habbit of just pirating the game when DRM gets in the way. I jumped through the hoop of installing a browser-VPN-Extension, clearing all cookies and then just buying the game from the very same account it wasn't available to before.
The game discount and that i did not renew my real non-logging highspeed VPN (perfect-privacy.com - also endorsed by nazis and carders, so probably the most privacy-friendly choice on the market) some years ago, is a major factor in that.
Next time i might or might not give in to the temptations of renewing that VPN account and starting to run bittorrent over my fiber connection like in the old days (i didn't had fiber back then though)...
It might be illegal, but it really felt like freedom.

While the major Unrated feature for most probably is the adult content, for me it actually was an accessibility issue as the crippled version was way too black in a lot of places, had white noise instead of proper speculars and featured blurry textures overall. That i can now see the genitals too is just nice to have. But the other shit made playing the crippled version too much an agony for me.

Thanks to GoG for making the upgrade available to me too - even though i had to jump through some hoops to finally get it. After all, it isn't their fault that stupid governments make stupid rules about what is degenerate art or too disturbing for their underlings to see.

Why in heavens sake was Agony ever created? It appears to be absolutely sick. If you're not likewise sick, playing this game will rot your sanity and you would be in a bad place without the fire while still living!