Eric suffers from the fact he's in a porn game and a fair amount of these tend to ride the same narrative. He's surrounded by either ladies or 'bbc' as alternative picks, and he's definitely not the protagonist, so no harem for him. So that leaves him with... well. You can guess. He could be interesting, but the spark isn't there for anything beyond the typical cliches atm. The best he could hope for is being the sweet and generous lover, but that's not typically 'sexy' enough for this genre, especially if he doesn't have big dick plot armor.
What is big dick plot armor you might ask? That's when the male character acts like a pushy obnoxious tall pile of trash, but it's okay, he's got a big cock which immediately makes 'em interesting, cool, and mysterious. Obvious sarcasm is obvious. But hey, some types love bad boys, so it's not wasted effort by any means.
Leo's a far more interesting pick due to his dynamic in my opinion, though I have a soft/hard spot for gals with something extra as well as transformation and change, especially if it's done by a means other than locking their bits up and treating them as less than human (which is usually the go to move in porn games). Honestly wouldn't mind seeing more of a route or a style where she's one of the girls, but also a lover/fuckbuddy of the MC. ...Come to think of it, I can't recall for the life of me encountering a porn game where the wingman/wingwoman is your trans bestie. Huh.
I could see Eric seeing the interactions with Leo from the outside and deciding 'this must be what the MC is into' and potentially falling down that rabbit hole, but then it's essentially Leo lite, and Leo has a great deal more content and grow to go before this would really make sense in the first place.
...Although the MC growing her harem of girls, regardless of their bits, is kind of an amusing thought.
One thing that does sort of leap out regarding writing and content regarding Leo is that despite several interactions boiling down to 'you aren't defined by your sex' (or you are) and such, that seems to be by and large all the MC speaks to him/her/them about. I understand it's important to nudge Leo this way or that, but it may be interesting to pursue some stuff Leo likes too. Probably more about the family dynamic that was hinted at too. Maybe offer eventually to have Leo move in with you so they can stop living under the pressures and all too potent demands back home.
Go shopping together, try on dresses, go to the sauna, walk around the town with Leo all dolled up, maybe get drunk and have sloppy sex with some guys or gals, or eachother (or all of the above) are some fun story beats. I really do enjoy the going to the gym together angle, because it's sharing a walk of life. The PC is trying to stay fit, and Leo being part of that feels organic, and kind of cute. ...Actually, come to think of it, it could be neat to have the heroine, Yara and Leo all running together. Or supporting the change along with the MC.
If Leo's friendship stat is high, then it should stand to reason that they are fond of the protagonist as well, so Leo attempting to repay the MC for her guidance and friendship seems on brand too. Maybe a gift or a date of some kind.
That sort of follows for the other girls, to a degree. A little friendship extended from them, or a potential date here and there would go a long way. Yara is at least proactive, and there's a bit of a fun dynamic of exploring the physical hobbies and the push and pull of a potential relationship. The BBC new world angle is... not my favorite, but that's fine. I have nothing against big dicks regardless of the pigment attached to it, (far from it!), but the whole subservient shtick literally being rammed down our throats can grow a bit tiresome sometimes. Like, we're supposed to be this willful spitfire that is determined to become the Prom Queen, at least initially. There doesn't seem to be a whole lot of that. If anything the writing seems designed to write the MC as a thirsty chaser, where if we are being honest, the men would likely be tripping over their own dicks trying to gain her attention.
Hm. I suppose that's another part of it. The MC's motivations could use a little more fleshing out here and there. Like, clearly there is the title, but why are they aiming for it? Then again, hot college student doing hot things and currently just living for the here and now also works.
Ack. Wall of text is large, looming and scary! All of this nonsense are suggestions at best, mostly musing out loud, haha. Sorry not sorry.
Game remains a fun romp, clearly interesting enough to get the ideas flowing.