It's a little soon in the process for me to write a review, so I'll drop a couple of thoughts here.
First, I commend you for creating a game that differs significantly from most in the genre. I don't have a lot of patience for games centered around high school or even college (most college-themed games on here are nothing more than a fifth year of HS). The themes in this game are more mature and nuanced and that's a good thing.
Second, it seems to me you have multiple writers working on this project. As I progressed through the twins' story line, the writing was more fractured and obtuse and contained elements that detracted from, rather than complimented, the plot. Melanie's story line, on the other hand, was more coherent, and had less grammatical and composition errors. I would be very careful to not allow the script to run off the rails as it does in so many of these games.
Thirdly, I encourage you to start including top-shelf animations in the game. You may have this already planned and if so, disregard my advice. Good animation can really add a lot of polish to a game. Simple things such as eye-blinks really make a difference.
Fourth, you need audio. As a professional video editor (which includes audio engineering), it is frustrating for me to see how little effort is placed in audio fx for these games. There are many free and/or low-cost options available for obtaining audio assets. I would encourage you to spend time making that happen.
Lastly, I will talk about one pet peeve of mind. I see this a lot in these games and I understand we're all wired differently, but the use of models that appear to be 12-year-old girls is jarring. The twins fall into that category and it would be nice if they actually looked age appropriate.