Digital games that are worth playing by older people are a new type of digital games that can reinforce and exploit the strengths of older people as individuals and game players rather than merely compensating for their limitations, reduce isolation and foster socialisation, both offline and online, and improve the physical and psychosocial wellbeing of older people. The research conducted in the WorthPlay project aims to enable an understanding and development of these types of digital games, and is grounded in ethnography, participatory and iterative design, and experiences of digital game play. This research will be conducted within the context of designing, developing and evaluating a prototype of an online game that is worth playing by older people, by involving and engaging in the research a user group consisting of older people of mixed gender and expertise playing games, and relevant members of their social circles. WorthPlay will take the state of the art of human-computer interaction research with older people and digital games forward by producing a human taxonomy of digital games for older people; providing a deeper understanding of everyday digital game by older people, of the challenges and opportunities of emerging human-game interaction styles and gaming platforms to improve the accessibility and playability of digital games for older people, and their physical and psychosocial wellbeing, of game adaptation to individual users, and of cultural similarities and differences in digital game play. WorthPlay will also improve relevant methodological aspects of human-computer interaction research with older people by looking into ethnography, user engagement, and iterative and participatory design, in out-of-laboratory conditions over extended periods of time. WorthPlay will also develop a pipeline to integrate the technology and research created during the project into marketable outcomes, and develop original methods of marketing digital games to the older population.