Developing games is time-consuming and costly. Overly clinical therapy games run the risk of being boring, which defeats the purpose of using games to motivate healing in the first place [ 10 , 23 ]. In this work, we adapt and repurpose an existing immersive virtual reality (iVR) game, Spellcasters, originally designed purely for entertainment for use as a stroke rehabilitation game—which is particularly relevant in the wake of COVID-19, where telehealth solutions are increasingly needed [ 4 ]. In preparation for participatory design sessions with stroke survivors, we collaborate with 14 medical professionals to ensure Spellcasters is safe and therapeutically valid for clinical adoption. We present our novel VR sandbox implementation that allows medical professionals to customize appropriate gestures and interactions for each patient’s unique needs. Additionally, we share a co-designed companion app prototype based on clinicians’ preferred data reporting mechanisms for telehealth. We discuss insights about adapting and repurposing entertainment games as serious games for health, features that clinicians value, and the potential broader impacts of applications like Spellcasters for stroke management.