You need Mary to go bowling with Marsha, what doesn't happen if you are on her path. Then there's a shitload of different scenes (30) depending on earlier choices and/or stats (souls/witchcraft, JoCest, NatCest, JoCest
and NatCest, Marsha banged >= 3, JoVirgin, Prowess, Energy).
You'll need a little more to get most of the scenes.

Even with 30+ playthroughs i'm still missing two scenes*.
*Edit:
I don't think they're even accessible because the choice between investigating souls and witchcraft makes a whole lot of difference on your energy when you get into the family games part. Choosing souls i am able to gather a maximum of 37 energy when the family games start. With witchcraft i only make 6.