Your critique feels disproportionately harsh for what the game is trying to do. From what I can tell, even a quick run through the story makes it clear the focus is on presenting the player with difficult choices and branching outcomes, something you yourself acknowledge. Given that structure, it also seems intentional that some characters come across as reserved or broadly defined, since that allows for player interpretation rather than forcing a rigid personality onto the experience.
It is also worth considering the scale of the project. The game contains a significant amount of content, and expecting every route, character, and interaction to be consistently refined to the highest possible standard is not especially realistic. There are going to be trade-offs in a project of that size, particularly for an indie title developed with limited resources.
The point about clichés also feels overstated. When a game attempts to combine multiple narrative threads, themes, and routes, some overlap with familiar ideas is almost inevitable. What matters more is how those elements are used, and dismissing them outright without engaging with their execution does not really add much to the discussion.
Some of your claims would also benefit from actual support. For example, stating that the backgrounds are taken from the public domain is a serious assertion, but you do not provide any evidence for it. Without that, it reads less like a critique and more like speculation.
More broadly, the tone of your comment makes it difficult to take seriously. Rather than building clear arguments, it often relies on exaggeration and dismissive phrasing, which gives the impression that the goal is to vent frustration rather than offer a thoughtful evaluation. Calling it one of the worst visual novels you have ever played, while also acknowledging several strengths, comes across as inconsistent and overly dramatic.
There are valid criticisms that could be made about the game, but they are buried under sweeping statements and a lack of nuance. A more balanced and precise approach would make your points far more convincing.