James Noir's Hollywood Crimes is a puzzle adventure game set in the 1960s. Players take on the role of contestant on a TV show called The Incredible Puzzle Masters, where they must solve puzzles to reach a certain score and advance through the rounds. Alongside this, players help their friend, now with the FBI, solve a murder case involving a serial killer targeting previous winners, leaving clues in puzzle form.
During each round of the show, there are twelve puzzles to choose from, each worth different point brackets. By carefully selecting which puzzles to attempt, players can aim to beat the minimum score and secure more 'fan letters' containing additional puzzles and hints for the killer's puzzles. In-game features include a semi-transparent overlay for writing or drawing on puzzle sheets with the stylus, a hint system, and the option to restart or abandon puzzles without penalty.