An illustrative interactive content delivery system includes an interactive content player device (player device) and an interactive content provider system (provider system). As the provider system transmits a live video stream to the player device, the player device detects a first event marker in the live video stream, accesses an executable data object including data representative of an interactive content instance, and executes, based on the executable data object, the interactive content instance in accordance with interactive input provided by a user of the player device. During the executing of the interactive content instance, the player device detects a second event marker in the live video stream and subsequently discontinues the executing of the interactive content instance. Corresponding methods and systems are disclosed for both the provider system and the player device of the interactive content delivery system.