In 'Chrono Chums: Who's There?', players take on the role of Kai, an unassuming librarian who discovers a peculiar pocket watch that allows them to traverse time. Each choice made sends Kai to different eras—like the roaring 20s, the distant future, or ancient civilizations—with unique sidekicks (the 'Chrono Chums') from each time period who share their quirks and skills. Players must gather clues, solve mysteries, and engage in witty banter while piecing together a timeline that has been tampered with by a malevolent time-fiddler. The game combines humor, suspense, and interesting historical factoids in an engaging narrative that challenges players to use their companions wisely as they navigate the complexities of time travel.