A 'cthulhu visual novel' could be about a journey into the dark and Lovecraftian universe. It may tell the story of a protagonist who stumbles upon the existence of Cthulhu and the otherworldly horrors that come with it. This could include facing strange cults, eldritch locations, and the psychological terror of realizing the insignificance of humanity in the face of such cosmic entities. It might also explore themes of madness and the thin line between sanity and insanity.
It's likely a visual novel related to Cthulhu, which is often associated with the Cthulhu Mythos in horror and dark fantasy. It might involve a story set in a world influenced by the ancient and powerful Cthulhu, with elements of mystery, horror, and the unknown. Maybe it has characters who discover secrets about this terrifying entity and its impact on their world.