Hell Diary is a single-player adventure game in which players explore a surreal dream-world that represents Hell, navigating through various environments and solving puzzles. In this game, players follow Eun as they journey through the dream-world of Hell, encountering strange characters and uncovering mysteries within this eerie landscape. It stands out with its unique focus on item-based exploration rather than traditional effects, featuring companions with their own tools and abilities, and emphasizing atmospheric storytelling and immersive environments.