In 'Hello, Goodbye,' players assume the role of an introverted linguist named Theo who inexplicably receives a series of cryptic greetings from people he never met. When each greeting mysteriously appears in his dreams and impacts reality, he embarks on a journey through a web of forgotten conversations and lost connections. As Theo uncovers secrets buried within each phrase, he must navigate a vibrant city, solve puzzles laden with wordplay, and interact with an eclectic cast of characters, each with their own stories. The challenge lies not just in finding the origin of these messages, but in choosing how to respond—each decision shaping the outcome of his adventure and the fate of those connected to the messages. The game's unique interface allows players to visually construct responses, altering the narrative and unlocking various plot twists in a comic and dramatic exploration of language and trust.