Where do you find them? I just saw by chance through the galaxy 2.0 that there was a free game the other day. Haven't seen any previously while on the website. Are giveaways only announced through the galaxy 2.0?
I know there is a list of some free games, demos, dlcs too. But they are free permanently i think. Do the giveaways show up on that list?

They are mentioned on the website's front page when they happen : https://www.gog.com/
Also when it does there is also some news about it in the general section of the forum.

Here ya go:

https://isthereanydeal.com/