In 'Hello, Whose Nightmare?', players take on the role of a dream detective named Sam who can infiltrate the nightmares of various individuals plagued by deep-seated fears. Players must navigate through surreal dreamscapes, solving puzzles and confronting manifestations of the dreamer's psyche. As Sam delves into each nightmare, they will uncover dark secrets and face moral dilemmas that challenge their perception of reality. The choices players make will affect not only their mission but also their own sanity as they begin to question who the real monster is.