The art does its job, although all the sprites staring directly at the camera gets a little monotonous to look at. If there's an area of development, it might be the shading, lighting, and the color choices being so simple that they don't really evoke a mood; the main image isn't quite strong enough for its role as the visual centerpiece.
While I'm not familiar with the main work this VN is a part of and can't judge it in that context, the frame story doesn't really justify its inclusion and just eats away some essential simplicity here. There are enough narrative layers that it starts to hurt the story, and most of the visuals exist for the least interesting parts as well. It doesn't help that the interpersonal conflict feels like it's all stated instead of dramatized – you don't get enough about these characters to be able to engage emotionally or for a true sense of dialog to emerge.
For something this small in scope and intending to present itself as a standalone work, I'd shift the focus towards the monolog, which does have compelling bits of historical description. It's a classic setup for a short story burdened by all the extra fat.