Anyone that plays sports, either professionally or recreationally, is at risk of suffering a sports-related injury. Anterior Cruciate Ligament (ACL) tears are one of the most common injuries to obtain within team-based sports. This injury can carry long-term consequences and it is important to follow the rehabilitation process in order to increase the chances of a good recovery. This is key not only for sportperformance, but also for day to day activities and to reduce any injury-related pain. Although the Importance to follow a home exercise programme (HEP) is broadly explained to patients by their physicians, few of them adhere to it. This work investigates the barriers faced by patients and aims to address the main challenges. The work focuses on the design of a game called Cosy ACL, which aims to increase adherence with a home exercise programme by taking cosy gaming elements and Virtual Reality. Cosy ACL immerses users in a slow-paced world to explore while at the same time completing their daily rehabilitation exercises. A user-centered design approach was followed to test different features and interactions that could affect adherence of the users. The novelty of a slow-paced and cosy exergame was well received among the participants who tested the game, who also reported feeling excited to continue playing and exercising. This work highlights the potential of novel exergaming approaches which are tailored to different gamer types. Based on the findings, recommendations for the design of exergames are presented in order to address the barriers that patients face with the aim of ensuring long-term adherence with home rehabilitation programmes for improved recovery outcomes.