That's a good idea. I was thinking about something like that. Back when the game was really hard, I was thinking about a system where, however many days have passed by when you finish the game (even by losing), they convert into bonus points. You could then use these bonus points to buy bonuses in the title screen, which boost all future playthroughs. But, it became too complicated, and it seemed to contradict some of the other design choices. For example, I didn't like that some games in the archive wouldn't look impressive just because they didn't benefit from future bonus purchases. Ultimately, I decided to go with the current bonus system, instead.
I did also think about having "feats", like if the main character gave X number of blowjobs, then she wouldn't take as much morale damage from giving blowjobs after that. But I kinda tabled that for now. I think the gameplay is complex enough as it is. I could try doing something like that in the future. But there's a lot of stuff I want to prioritize first. For example, I want to flesh out the evening events (pool, bar, etc) some more. I also definitely need to introduce more lewd scenes into the game, now!