FYI, I quit this game after finishing the third part.
I don't enjoy giving bad reviews especially for the smaller, relatively new project, but there're a few annoying aspects in this game just irk me a bit too much, so take it with a grain of salt:
1. MC. The single most annoying aspect of this game: the ugly face and short height combined with too much of the dev's self-insertion (I'll talk about it in the second part) just make me really hard to enjoy especially when this game is basically a kinetic novel with no substantial relationship choice to pick. Honestly, seeing him and his TALLER not-sister walking side by side is just not a good selling point.
2. Self-insertion. The first two parts of the story are OK, but starting from Part 3 the MC suddenly rants about how hard it is to be a porn game dev and how envious he is towards the big shots of this industry. I mean, I really get it. Developing a game from scratch especially when the initial financial incentive is almost minimal is quite challenging and frustrating and I do hope the dev can fulfill his wish one day. But we as players just want to chill and fap when playing these games, not having to add some unnecessary psychological burdens that aren't us to take. In addition, there're also too many words spent on MC's inner thoughts and it's tiring to read. As one reviewer said, You really need to emphasize the "visual" part of the Visual Novel: show, don't tell.
3. Lack of agency. MC and his not-sister clearly are still at school and even though we can adjust the age of each character, your not-mother's complaint about MC not having a job will not change, which is even more jarring because MC's more childish face and short height. It's at this point I realize we have no agency in this game (shocking I know, considering this is essentially a KN), and the fact that both the two adult LIs have done porn before doesn't help either. You're bound to bang them one way or the other, yet such lack of freedom is just not my cup of tea.
Overall, I can't really recommend playing this, which is really sad considering Incest, Harem, and Pregnancy are my TOP 3 tags, but the horrendous MC render, the dev's self-insertion, and lack of agency really don't make the game an interesting piece to taste.