Intergenerational games to be played by grandparents and their grandchildren can be mutually beneficial for both age groups: breaking with age stereotypes, linking the learning and leisure needs of both generations and encouraging communication, solidarity, and social connectedness between generations. Due to the COVID-19 pandemic, it was necessary to switch from colocated physical intergenerational play to online experiences. This type of experience, in which grandparents connect from their own houses to participate, represents a challenge in terms of recruiting participants and carrying out the online sessions, due to grandparents' technological insecurities and their reluctance to play videogames. Besides, intergenerational games have to be carefully designed to promote symmetrical interactions, fun, and engagement on the part of both age groups as well as to develop easy to use interfaces. In this work, we present an online storytelling game designed to be played by family teams formed by grandparents and their grandchildren. The guidelines followed, the assessment tools designed to evaluate the intergenerational dynamics and the emotions that arise during the experience are also presented. Results of the three online sessions carried out are presented and discussed.