Most of the JP playerbase dont read English so marking to them is like switching your phone to another language. Visual novels have two things going, creatively and story, if you can make a fun interactive game, you have a fun game or if you make a story the people will want more from the story. This is also true for books, people will look for their kind of book . I played your demo game for a bit to see your visual novel, it has many lacking features of visual novel.
There are no characters, you dont need characters but people will expect characters such as people expect actors in a movie. words are too small, way too small and they dont have that feeling of being read. no sound effects; you cant just rely on music and background. Basic renpy UI look, I think you selected a look and didnt do much.
Clearly the ads arent the problem, its the game being bear-bones, its a visual novel but lacks many visual novel novelty.