The mother's model is amazing. But for everyone curious, there's barely any content. It does say this is v0.1.1, so it's hardly a surprise.
You only have 3 locations: your bedroom, mother's bedroom, bathroom. You can't go to any other location, even though you hear women's voices from downstairs. I'd guess this is build-up for later. Your only real actions when the mother isn't around is study, shower, and sleep/rest to regain energy. Grind study to get it above 200, hug the mother whenever she's around to eventually grope her butt. Once study is past 200, go to her room at 22:00 to sleep with her and jack off on her body. Hugging her and jacking off on her raises Favor. As that goes up (you don't have a meter for it), you can ask her for money at 22:00 in her room (before sleeping with her). She gives you $10 and decreases Favor. Grind Favor to ask for money 2 more times to buy a $30. Then you get some pics from your sister and this version of the game ends. The mother shows up in your room every once in a while to kiss. You can enter the bathroom when she's showering but nothing happens.