As for NSFW ideas I've had a few:
1) An NTR game where you are in a house full of girls, you have to fend off the neighbours whilst pursuing and guarding them whilst outside the house, some you must leave behind and some not. But you can't be in two places at once right? In the first week a guy called Fat Dave is introduced as a lodger in the house, Fat Dave is balding, fat, ugly and I think you think you know where this is heading right? NOPE, plot twist!!! If you make friends with Fat Dave then anytime a rival tries to be affectionate with the girls he chases them and bonks them with a frying pan. Seeing the classic NTR trope guy but he turns out to be a loyal defender of your girls when not around but you, the audience and player don't know that. It would be interesting.
2) A game in which you play as an Orc hired to guard the daughter of a very wealthy Elven family in Elven lands but all the noble elven ladies fall for your big orc cock, including the daughter, her mother and others. In fact the nobles soon turn to political schemes, bargaining with each other over who gets you each night. The elven males, subdued also attempt to bargain to have you servicing the females of their families rather than the others, at last you are an orc with a harem of an entire elven nation, men want to be you, females want to fuck you, but you? You are an Orc, THE Orc, you are: Orc Chad x 9000!
3) A game in which you work dead end jobs paycheck to paycheck, come home to find your wife with her bull, grab yourself another Mountain Dew and start the nightly cycle of Moderating F95 Threads.
4) A game in which you play as as invisible cupid at a party and you can hit as many different combinations as possible, F/F M/M M/F, F/Animal, M/Animal, F/Inanimate object, M/Inanimate object etc etc.
5) A game where your semen is addictive and you slowly corrupt everyone around you into your sex slaves.
I have more but that'll do for now...