Testament of Sherlock Holmes

The gameplay focuses on investigations, with an open-world environment that allows players to explore different locations and follow leads or ignore them. Characters can run to travel faster, and items in the environment are highlighted with a magnifying glass. Players can inspect these items up close to gather clues or perform actions like moving an item. The game also features puzzles that require deductive reasoning, where the player's answers affect how the evidence is used afterwards.

The game offers various ways to progress, including conversations with suspects, where different approaches can be used to catch them off-guard. Other elements of the menu provide context, a summary of dialogues, decorations, and honors, as well as a map of London. The game also includes a "sixth sense" system that provides hints when needed, which can be activated based on the chosen difficulty level.