Looks promising, but so much is unfinished. I'm not sure if anyone found a guide, but this is what I'm aware of:
Jun: Just the intro content
Cassie: Fight minigame, followed by nipple vore minigame. Whether you win or lose, there isn't much content after. Either game overs, or "wait for future update" type messages. (Winning then refusing to play the nipple vore unlocks an additional scene with layla, but not much otherwise).
The other two just have their initial interaction, and whether you win/lose there doesn't seem to be much other content unlocked. (Except some unbirth scenes if you lose that game, then "wait for future updates").
Maybe I'm missing something, but I don't want to spend hours looking at the same repetitive and often broken mechanics/cutscenes to find it.