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My dude, my guy, I'm a huge fan of full incest games where you can get your full blooded mom and sisters pregnant (and other female relatives too), or fuck and creampie them at least even if pregnancy isn't in the game yet or at all. Family Venture and Tales From The Unending Void are two really good examples.
But yea, I'm in favour of creampies for mom sisters aunts cousins, and grandmothers depending on the various character ages. Grandmas House is a good game for that.
Step family incest isn't terrible, but it's not great. It always feels like the game has been censored. Which to be fair is sometimes the actual case. But that can be typically fixed with official patches that restore content by changing the script of what what the player reads and what the characters all say etc.  Grandmas House is again a good example of that. 

Depth's Revival has a patch/mod that changes the script and adds in incest scenes that had to be cut because they couldn't be changed from family without changing the story completely.

The worst thing you could do is go down the Landlady and Housemate route, where your mom is your "landlandy" and your sisters are your "housemates". It's painful to play and read and just annoys everyone. Everyone knows it's a censored incest game. Stories that use this "workaround" make no sense because they're typically obviously written first with full incest then changed after, making everything weird. There's no taboo about wanting to fuck your hot landlady or housemates. Why are you do loyal to your landlady and housemates? So much stuff is just stupid. 

But I've ranted enough for one comment haha. 

My point is, if you can and are willing to, I'd be delighted to play a game by you where you get to fuck and cum in all your female relatives, and any other characters you have in the story. And ideally get them pregnant as some point. Oh, I say all, but I personally don't enjoy playing games where you're the father and you go after your daughters.