From my own post in another topic: - What are the assessment criteria? It is hard to specify them - I speak to my interlocutors aloud. They laugh. Oh, yes, we have battles, admits Jacek. More than once it is a struggle, drawing additional arguments, Marta adds. Sometimes people who care about a given title try to convince those who look at him unfavorably. The guidelines are fluid, based mainly on the fact that the game must represent an appropriate level of quality and be tailored to the GOG's user. RPGs and strategies are therefore safe categories. Sports games are apparently an absolute "no". The appearance of FIFA on the platform would trigger numerous question marks, as well as the lack of Divinity: Original Sin 2. It is known that our users are core, hardcore players, emphasizes Jacek, so more casual titles have uphill.
Original source (in Polish)