Wow, this game is a fucking awesome start. It has massive potential with a solid core at the beginning. It has so many cool little powers, and I can't wait to see where it's going. Keep up the good work. The strengths of this game are the writing / coding first and foremost and should maintain that focus.
Here are some ways I imagine it can continue / expand / improve:
"Dress Up System / Work System" As far as I can tell the sister only has 1 set of clothes she can wear as of yet. I like how you can buy the clothes off of the pharmacist and store clerk. Those should be wearable by the sister. Couple that with the "Personality Change" power. That means the sister can go get a job doing anything. The sister should have various sources of income. From begging on the streets, to being to a prostitute, to more on the up and up work like jobs at the Pharmacy or Tutoring or whatever.
"Breaker Box" The house should have a breaker box. Maybe you don't want to run around the house and turn off all of the lights all the time. The ability to turn them all off at once so you live like it is a blackout to save money would be a simple solution.
"Sleep Walker / Out on your Feet State" The sister can be asleep or awake currently. It would be interesting to add a 3rd state. One where she is neither fully awake or fully asleep. Where she is on autopilot to some extent.
"Town People / Some level of randomization" I don't like how the streets are always empty. You need to see some random people on the streets at some points. It feels wasted to have the ability to get the sister out of the house, but nothing to interact with.
"Expanded Town" It would be nice to have a "Rich Side" and "Poor Side" of town. With various places to go and people to interact with and jobs to do.
"More Shops" There needs to be more to spend money on. From clothing stores, to costume stores, to sex toy shops, and more. More little things to buy and use is always a plus. There could be stuff like "Shady Drug Dealers" things you can buy should not be limited to the legal.
"Jail System / Wanted Level", some of the stuff the sister does should be able to land her in jail. Maybe be able to break her out of prison, bribe cops, manipulate them to forget like you do with the sister and so forth.
"Better Soft Reset Options" currently if the sister dies, or flees in terror etc. It automatically resets her sex points to 0 all around, and have option to reset affection points to 0. I'd like it if you could choose to keep sex stats, or not in that menu or just reset everything or like just reset virginity.
"More Personalities", be nice to be able to treat the sister as a "Pet Girl" for example. Give her the mind of a cat girl / dog girl. Maybe you can make her think she is your "Wife" and newly weds and not your sister. How about a Dominatrix personality / Bully personality. Turning her into your bully would be real hot I think.
"More Attributes" You only really got "Affection" with the sister currently. That could be broken down into "Trust" and "Love" and "Lust" and even stuff like "Happiness" or "Submission". It's begging for more.
"Household Chores" the house should get more dirty over time. You or sister could clean up around the house, or maybe even hire a maid to come over every so often.
"Bodily Changes" Preggo belly / giving birth are a must!
"Possession" where you shift your spirit into the sister and walk around and interact with the world from her perspective.
Lots of ways this can continue to unfold! It's good now, but it has so much greatness it can be!
