Mystery P.I.: Portrait of a Thief challenges players to become a private investigator and track an art thief to recover missing paintings recently stolen from a private collection. The game features 18 missions with multiple locations in each, including 9 DS-only locations. Players can also collect awards, encounter new characters and keep track of their game in the case log while unlocking secret gameplay modes and mini-game free play. Mystery P.I.: Portrait of a Thief also provides a dual screen interface and touch-screen functionality.