Idea:
Title: Tiger Mom
Synopsis: Mother (preferred caucasian or east asian) has an older daughter and younger son. Daughter is kind of a loser/doesn't get good grades. She wants better for her son so she micromanages his life.
Main characters:
Mom - busty/fit/type A. Husband either died/divorced/loveless marriage/he is not around for simplicity. She is super focused on son.
Son - Typical young male character in your games, like from House Wife.
Side Characters:
Daughter - Older sister type, like from House Wife. Except maybe goth/rebellious to fit her character.
Son's friend - same body type as son, though difference race (black if son is white, white if son is asian)
Assortment of milfs and older females. Number can vary depending on scope (teacher, tutor, mom's friend, etc.)
Storylines/endings:
1. Pure love - Mom develops feelings/helps relieve son to maximize his achievement and shuns other females. (They could be made available for son's friend, or not)
2. Harem - Mom develops feelings + allows son to explore with other women, including his sister. Son's friend is humiliated.
3. NTR 1 - Mom pursues son's friend to keep him from distracting her son. Daughter becomes involved as well. Son may or may not pursue other women. Son is none the wiser.
4. NTR 2 - Son's friend ends up with all the women and son is humiliated.
Setting:
- Mostly at home. Potentially after work if you want Mom to have a job.
- One or two locations outside of home where other milfs are, depending on scope. Small town feel works well for this. Seashell whispers but smaller map.
Gameplay:
- you may be able to play as son or Mom, though I think mom as playable character makes the most sense.
- build desire for and between family members, like House Wife
- Complete quests/events to further actions outside household/with son's friend.
I feel like whatever engine(s) you currently are comfortable with are good for this and there's a large market but idk.