That's fair, tho this is actually a fairly well-known genre of visual novel. It's mainly known of in the west via the When They Cry series of Higurashi and Umineko but there's plenty of others that use the same format. The specfic term for a VN with no choices is "kinetic novel" in most western circles? but a kinetic novel is also a visual novel. Or a sound novel, sometimes, though also a visual novel. The argument being that bgm, background and music are used in the same way videogames use them to enhance a story.