One thing I can assure you of is that ending a game when you diverge from a particular path is one of the worst things that you can do. You may not have meant it in a strictly literal sense, but one of the key points of fairytales is that they always have a happy ending, whereas more often then no, life does not. It would take up more time, but tailoring an ending to almost every potential outcome is extremely beneficial, but another thing is don’t be afraid of the bad endings. I’m not saying include game-over screens or anything but again life doesn’t have good endings sometimes. It’s perfectly okay to have good endings in the storyline, but a happily ever after isn’t always on the cards. I love less than perfect endings; resolving the conflict is a must, but it doesn’t have to be happy and sweet. Sometimes it can be utterly realistic.
But thank you for the consideration.
Okay, I expected the fairy godparent as a potential RO, but I’m sorry…the King/Queen? That would go over tremendously, wouldn’t it?
Cinderella: “I’m afraid I’m leaving you for someone else”.
Prince Charming: “What?! Why?! Who is it that’s taken your heart away from me?!”
Cinderella:"…Your mom. Surprise?"
That would probably be clever if done right though; by all means give it a shot.
Correction: that’s all the tales have given us. This is your story. She can be powerful, intelligent, alluring, convivial; take your pick. Or she could be a kind heart with a pretty face and a thick skull as you suggested. Again, your choice.