I played this yesterday. It have an interesting story and the correct amount of NSFW scenes. It have a mysterious side that makes this game different. It remind me a little of "Lost" TV series (a mysterious islands where weird things happens... and a couple of flashbacks) but is precisely this what allows the plot to be sexual without force the situation. On the other hand, I enjoyed a lot how unpredictable it can be. There are a couple of scenes where you think "ha, here is going to happen this" and suddenly it doesn't an you say "Whaaaaat? well played writer" Specially the scenes between the protagonist and the mother.
About the writting I don't have anything to complain. Well, the explanation about the Alice body shape is... "forced", but understandable in matter of legal avoidance of "problems". There are a little of "intergenerational plots" in the story right? some kid of fetish about it? If you analyse it, most of the characters have a high age difference, like the protagonist with Yvi and the protagonist with the mother. On the other hand Alice is an undercovered age difference too, but that not specially an issue, just a curious fetish. Of course some people can "scandalise" with this, but others would enjoy it. I just wanted to comment it.
In the graphical part there are two things that I would do different. First is the exaggerated penis size of the MC, and the other is Alice face. There is something there different in her face that doesn't match. Maybe is intentional? But it looks even a little creepy. Is like this 3D model belongs to somewhere else. I think that if this character looks in the way the readhead girl does (not the same, but the same kind of textures and that considerating that they may be the same... hypothetical age
) it would be better. On the other hand I loved the work done in the older sister, she has lots of details and quality, like the rib marks, perfect breast size... I like the work done here. I also like the pubic hair in characters like the mother, pubic hair is always appreciated