It’s not like the characters are badly written or just there for the sex.
Yes it is. The MC goes from raping all the girls in their sleep (including his sister) in act 1 to be against even kissing his sister in act 2. Certain characters like Ada and Annie also progressed way too quickly from hating the MC to liking him. The writing is probably the weakest part of the game.
And I don’t get why you find it hard to understand. It’s a porn
game. Meant to have interaction and story. If it was just the porn aspect that mattered I could look up hentai instead of playing the game. The problem is there hasn’t been any story advancement at all despite act 1 setting up some good story beats. Either way, no way will the game progress to the end at its current rate which is disappointing.