Alright, I have to say something. This game has been eating hours of my life recently. Something about the gameplay, the emphasis on replay and path exhaustion just scratches a deeply nostalgic itch. Without feeling dated, it harkens back to simpler times in my life. The achievements and bonuses add an interesting knowledge dimension to gameplay and planning and the rqpid update pace and constant changes to flow keep things fresh.
That said, I don't think I play the game right. I enjoy trying new approaches to a first loop and seeing how far I can get in one loop. I often don't make it through a second in the same version cycle (Unless anal scenes get added, but more on that later.) Overall this challlenge has been getting steadily more interesting as content gets added. As of this cycle there's a relatively straightforward route to get with Susan, Rose, Katrina and Carol while getting up to Anal with Melanie and Oral from Jane and Olivia. The new bought books add further options and more items are going to improve what's possible.
That all said, I think the late/post game is where things are slow at the moment. I don't feel deep investment in saves is all that interesting at this point in development. Part of this is there's a lack of content that rewards it. You can see most of everything for all the girls in a few runs and there's clearly easy girls for content (Suszn, Rose) and some that are are harder (Melanie, Natasha) but at this stage, there isn't really a point to the whole "Gotta bang em all" content grind beyond this conent.
I think the direction to look in for that might be to do more with this reality being simulated. Rather than just incremental stat upgrades, maybe allow the purchase of upgrades to the simulation. For example: An exp upgrade that makes he Girls appear naked or an upgrade that allows you to instantly "cheat" out stat points for the girls a limited number of times per loop. Maybe gate these behind high coding. Or maybe the option to add restrictions/penalties to loops for extra xp on that loop .The idea being content options that change how the game plays rather than just more numbers.
In terms of sex scenes and what I'd like to see there, I'd love to more of the girls get filled out (no pun intended) with anal scenes, on which note the game tracking vaginal for exp purposes but not oral or anal also feels a little... short-sighted. Not to mention he popularity mechanics which seem to imply the rumor mill only cares about vaginal sex and kissing. I'd love to see an ass to mouth scene for one (or more(or all)) of the girls with an achievement for it, but that's very much just a selfish request based on what does it for me.