Aggres is a sequel to Zodiac. The search for the space archaeologist Dr. Dumas, who disappeared five years ago, has led the courier-turned-detective Boy and his assistant, the robotic Amaroid Marie, to a galactic megalopolis simply known as "The City", where they hope to find answers regarding the mysterious disappearance. Gameplay-wise, the game abandons the text adventure format of its predecessor and instead presents a set menu with verb commands (Examine, Talk, Move, etc.) that are used for combinations with on-screen characters and people to interact with the environment and advance the plot.