Which South Park video game was developed by Obsidian Entertainment?

South Park: The Stick of Truth is the South Park video game developed by Obsidian Entertainment. It is a role-playing game set in the fictional Colorado town from the television series and was written and designed with major creative involvement from series creators Trey Parker and Matt Stone.

The game places the player in the role of a new child who becomes involved in a fantasy war between South Park’s children. Its deliberately crude humor, visual style, character designs, and dialogue closely imitate the television show. Gameplay combines exploration, turn-based combat, equipment upgrades, companions, and parody versions of fantasy role-playing conventions.

The Stick of Truth was originally being developed by South Park Digital Studios and publisher THQ, but Ubisoft released it in 2014 after THQ’s bankruptcy. Obsidian’s involvement is the key distinction in this question: Ubisoft later published South Park: The Fractured but Whole, but that sequel was developed by Ubisoft San Francisco rather than Obsidian.