That means it's a fan-made unrated/uncensor patch designed for GOG version. The game itself is officially censored.
And holy cow, there's a reason it's censored. The dicks look like a pound of sausage still in the wrapper that you get at a grocery store. Also, the devs knew that the game would be censored so they didn't bother putting much effort into making any animations involving the penis line up properly since the censor blur would make it impossible to tell if things were connecting anyway (i.e. the tongue not actually touching the penis when the girl likes it, or the penis being inserted into the skin between the pussy and asshole, or even the penis peeking out of the girls' spine because it's so massive).
