Blacksad: Under The Skin is set in New York during John Blacksad's early years after World War II. The story begins with the feline detective being hired by a client, Sonia, whose father Joe Dunn has been found dead under mysterious circumstances. As Blacksad investigates, he uncovers a web of conspiracies involving drugs, blackmails, money, and hired guns. With the police suspecting a suicide, Blacksad must dig deeper to find the truth. The game is played in third-person perspective, with an action-camera that follows the character's movements but occasionally changes angles for a more cinematic feel. The player has limited control over where they look, but can explore what the camera shows. Hidden stickers can be found by moving the camera offset from its fixed position, and these can be accessed via the main menu.
Interacting with objects is often done in first-person perspective, usually when examining multiple items on a desk or similar surface. The player can select individual objects to interact with, but must do so before time runs out to avoid missing important information. Dialogue options are also available, with choices that affect character stats and potentially alter the story.
The game features an intricate system of character stats, with 8 different attributes that can be influenced by the player's actions and dialogue choices. There is no inventory system, as objects Blacksad carries are always with him and used automatically at the right location.
Blacksad: Under The Skin tells an original story based on the comic book series, and is not a game adaptation of an existing title.