I agree with every last thing you said, other than the trope issues you have with the game. I think that the whole "taboo incest fetish" thing isnt going anywhere. It is still a hugely popular fetish and i think many devs and authors should continue implementing it. Not all porn game fetishes need to be brand new, unique and innovative. In fact, I find it better when the fetishes are widespread, but remain the same tags they've always been. Personally I find the whole "roommates/landlord" thing annoying af. Either have the balls to go with what you meant for it to be, or create a completely different scenario.
You ARE right, however when it comes to flow, context and consistency... The author needs to clean that up, as it was obviously meant to be a taboo incest game, but they cleaned it up (horribly) for some reason. As far as the grammar, they should get someone that can translate (if thats what they did) into english much much better. Or at least write the language fluently and eloquently instead of making it sound like a third grader wrote this.
But other than that, I completely agree with everything else. And I also quite enjoyed the game. This site definitely has much worse out there...
Upvote for the great well-thought out review. ^_^