I want to explain something. I am German. So I am not here to dance around or sugarcoat my opinion. And that's all I do here - give my honest opinion and feedback. I dont want to diminish your work, your effort and/or time you put into this.
The problem for me is, that the story mode IS just a kinetic novel because I dont get any choices. So its either a sanboxy/freeroam game with choices or a kinetic novel. I have to admit, i just checked for the first choice in the standard and then in the story mode - so I assume that there are no choices, because that is what you said in the mode select.
So do your thing - I would like to play this with a "proper" VN story mode where I still can make the choices from the sandbox version and just miss some fluff that is added there and not mandatory for the progress of the story, but if you dont want to make that or think that it is not possible, that is fine. Then its just not a game for me.
Oh and I do play some sandboxy stuff (e.g. Girl Life), but not many and only very few really have a sandbox - most of them are "just" a VN with added steps/navigation.
So - just try to take some of the responses here into account for your project and go on. I just wish you and your project the best