You highlighted two major issues. This game tries to be something it's not, and does it in bad way.
Such game doesn't need an elaborate story. Foundation of story is already laid. MC got in trouble, now he has to get out, and while saving his ass, he needs to bed all the girls while roaming through locations. Of course, you can make sophisticated story into this, but game like this doesn't need a strong story in order to be good. Focus is at solving series of quests, this is not a novel.
Second thing, it's my impression that author and his patrons think "Stairway to Heaven" is powerful story telling mechanism... which is not. Like you pointed, it makes this game boring.
Ps, I am not trying to compare Lewdlab with anybody else, his previous game was good, and I still think this one could be redeemed, but change of approach is necessary. I only pointed out that Milfy City (go and fuck all sandbox) or COBD (visual novel with branching), are not boring to play.
On the side note, if you watch movie from online streams or torrent site, it doesn't mean you can't offer your observations.