Hey everybody,
I'm the dev of the game,
thank you very much for all your comments
No MMF is planned to be in the game, it's a typo.
Only MFF.
The game is named "Welcome to Our Family" Because in the next update, MC meets his new girlfriend, and she eventually invites MC to live with her family. And you'll be able to have some fun with her mom/sisters if you'll want, so technically not incest
As for the sandbox tag, I'm not sure yet which way I will go; it might stay a VN like it is now. But I still want the players to be able to choose which character to have fun with.