Mind control.
"What?! Arent there plenty of porn games with mind control?"
Yes, and most of them, like 90% of them, suck ass like the devs dont actually understand the fetish and why its so attractive to mc fans.
It often feels like mind control is just being put in there to have easy access to porn scenes. Then theres the fact that most western devs and therefore their protagonists lack any sort of imagination which makes scenes themselves really boring most of the time. Its usually just vanilla sex or blowjob with dull dialogue:
Protagonist: You are my slave, now suck my dick!
Slut: Yes master, i am your slave. I will suck your dick.
*proceeds to suck dick*
Games with only a few mind control scenes are guaranteed to be awful cause its obvious they were put in there just for the sake of variety. However even very popular games which supposedly focus on mind control are often hot garbage when it comes to depicting this fetish...
cough CK
cough