I played your game and I have to say, you wrote a really good story. I personally know someone who experienced something similar and told me a lot, so I can add a few observations and/or ideas.
1. Lena: You captured her attitude very well. One thing I would add: if the MC becomes assertive, Lena (if she wants to return to the MC) should take the initiative more often. This means events should start with her phone call, a text message, or even a sudden visit to the apartment door. They shouldn't be initiated by the player (clicking on the phone). This way, she'll try to arouse emotions in the MC to get back together. And if the MC becomes submissive, she'll gain even more confidence.
2. Natalie: It's clear that she's had a breakdown with the MC from the very beginning, but she doesn't give in to her emotions, which means she has a strong system of values and respect. However, she quickly gives in to them as soon as it becomes clear to her that the MC is breaking up with Lena. And that should be highlighted. Such a person will quickly fall in love and push for a long-term relationship, even a family. You even made this clear when you mentioned children, supposedly jokingly. She also won't tolerate MC dating other women. She'll be jealous.
3. Clair: She's MC's sister, and they have a pretty good relationship. Why, all this time, have they never once discussed what happened?
4. Iris: An interesting character because she forces the player to be patient. She doesn't get handed anything on a silver platter, and that's a good thing.
5. Riley: She doesn't seem like wife material, and that's a good thing. She's the opposite of Natalie and introduces.