The game moves away from a series of disconnected cases in favor of one set in 1898 London.

: For improved navigation, players can switch between third-person, first-person, and a classic point-and-click view .

While the game features ranging from Whitechapel to 221B Baker Street, critics have noted a "technical jankiness" typical of its era.

: A signature mechanic where players link clues and evidence to form logical conclusions. This system requires correct solutions to progress the story, providing a "hands-on" detective experience.

(2012) represents a pivotal shift for developer Frogwares, serving as the bridge between old-school point-and-click mechanics and the modern, cinematic deduction systems seen in later titles like Crimes & Punishments . Unlike earlier entries that often adapted specific Arthur Conan Doyle stories, Testament features an entirely original, mature narrative centered on the personal downfall and questionable morality of Sherlock Holmes himself. Core Gameplay & Mechanics

: The graphics are sometimes described as "rough," with notable issues in lip-syncing and "creepy" child character designs.