This article examines how the unique characteristics of Marvinter, an inclusive transmedia Advent calendar, affected its production and the individual media workers involved in this. In the native transmedia Marvinter project, a radio series and a mobile game were created and released simultaneously. Using ‘partly shared’ resources, the project was developed by two collaborating, non-profit organisations. Each chapter of the digital game had to match the corresponding radio episode. The whole had to be designed to provide a shared cultural experience that included people with hearing or visual impairments. The authors of the present article were part of the game development team and thus directly experienced the complexity of developing a digital game as part of a transmedia project. This article presents the results of a case study with an insider perspective. It is supplemented by semi-structured interviews with key people in the project. The transmedia nature of Marvinter was justified by the need to include people with complementary disabilities. Although sometimes associated with negative connotations of ‘naked commercialisation’ in transmedia contexts, the marketing strategy was here an important element in promoting inclusivity. However, owing to the concurrent work processes, game production became overly complex.