No girls for me too. And I don't see much adventure either.
NTR is less common in Japanese games than you think. Japanese games have only about 50% chance to be NTR.
The developers, HGGame, do love their NTR - about half of their games have "cheating" tag.
That's severely over-estimating it tbh.
It's more 50% of the TL'd games have that chance.
Since the genre is more popular among those who translate games in the first place.
You can see rough estimates by viewing the number of games with the tag on vndb, and DLsite, verses the total number of games. (while a game or two may be missing the tag it's a pretty good indicator).
You also have to bear in mind that porn games are in of themselves a niche media. (A growing one to be sure, but still niche).
So niche content itself gets over-represented. (also in part due to the fact, people in niches tend to pay more $, perfect example is how much money furries pay for commissions).