Thesis (MTech (Information Technology)--Cape Peninsula University of Technology, 2017. / Active Video Games (AVGs) are a form of video games that rely on gamer motion as the main source of interaction between the AVG and the player. These AVGs serve a number of purposes, such as medical rehabilitation, education, social development, and motor skill development, among others. Prolonged play of AVGs is not sustainable as gamers lose interest in playing AVGs after the initial period of acquiring them. Therefore, the following research question was posed: “What design factors contribute to an engaged and immersed AVG experience?” The aim was to explore the inhibiting and enhancing factors influencing engagement and immersion among AVG gamers, as well as to develop a theory of AVG design. Constructivist Grounded Theory (CGT) was used as the methodology to carry out this study, which adopted an inductive approach towards the research to construct a theory firmly grounded in the data. Play Active Theory (PAT) is the outcome of this process, which explores the engagement and immersion factors related to AVG design as well as the abandonment and replayability of AVGs. PAT was compared to existing engagement and motivation theories as part of the CGT process, and further refined. In closing, the research question was answered and the aims of the study were met. A reflection account of the research journey concludes the thesis.