Electric Agents is a multi-player game that uses augmented reality on mobile phones to facilitate in-room collaboration and promote joint media engagement around interactive educational television content in the home. Joint media engagement describes 'collaborative' consumption of media and has potential learning benefits. Our research examines whether technology can support joint media engagement, through the use of a series of prototypes that combine handheld augmented reality with web-based video. In pilot testing, sibling play patterns showed evidence of the kind of in-room collaboration and joint media engagement that previous research has shown to facilitate children in making sense of media content.