An incest-focused game - which Family Affair at least purports to be - lives and dies on the interactions between characters. You, the player, must believe that the characters are related, that they have all the interesting and complicated baggage that comes with family, and that they're ignoring all that and moving past the normal social mores to something forbidden and, hopefully, erotic.
Family Affair has none of that.
Firstly, no character has a personality. Not one. They're all defined by their appearance or the way they fuck the protagonist. The MILF is just a MILF, nothing more. She has a job, but who cares what it is! Does she have friends? Preferences? Opinions? Nah. But after ONE glass of wine she'll fuck her son with no build-up or preamble.
One sister was away from home from studying abroad and is now back. Where was she? What did she study? Why did she stop? Why is her friend - a friend she met abroad - suddenly in the family kitchen, apparently living in the same city as the protagonist? Who cares!
The other sister is a ball-buster, but that's a single trait, not a character. She doesn't live at home because their mom fucked her boyfriend after prom. Wow! That's conflict! Could it be used in the story?! Nah, that's boring and isn't sex. Let's completely ignore it.
The above applies to all characters, but calling them characters is wrong. They have no character. They are assigned a relation to the protagonist, from 'relative' to 'bar owner' to 'school friend,' and that's where they end. They have very few interactions that aren't sexual, and those rare moments don't advance story or character in any way.
Oh, and there also isn't any story. None. Nothing we're moving towards. No goals. Nothing on the horizon. Literally not one character, protagonist included, cares about anything at all. But who cares! Story doesn't matter! There's porn!
And the porn, by which I mean the renders, is....average to good, with one glaring exception. The pursuable characters all look decent, and notably one trans character has had an enormous amount of polish put in. But the glaring exception undermines all this: the protagonist looks awful. Of all the places to skip polish, the protagonist is not it.
He looks amorphously young, somewhere between early teen and late-blooming adult. He is sickly pale; he literally looks ill, as though he's constantly pulling all-nighters and never sleeping. His face is hilariously ugly. A bulbous nose, bulging eyes, and awful hair complete his look. What look? Twat of the Year.
The protagonist is so genuinely off-putting that he undermines any lust in a sex scene the second he appears on screen. But it's not as though there aren't normal looking men in the game. At one point his friend Dan is introduced. Dan is meant to be a generic, throw-away guy of absolutely zero importance, but compared to our hero, Dan is as handsome as a Greek statue. I wish Dan was the protagonist. Anything but what seems like deliberate ugliness.
There are also 'video' sections, but they're just rendered stills repeating and are laughably bad, and should probably not even be bothered with by the dev.
Gameplay-wise, there isn't any. You're presented with the occasional choice but they're all meaningless, since each one is choosing from '1) Obvious Sex Answer' and '2) Obvious Not-Sex Answer.' They don't offer insights into character, just useless punishments for picking wrong.
All told, Family Affair is lacking in almost every context. If - if - you skip all meaningless text and jump from sex scene to sex scene, you might have a decent time, but you'll still have to stare at the ugliest protagonist I've ever seen. There's really no winning with this one.
Unequivocally not recommended.