“…the study by Falk et al (2001). Also, we excluded 12 studies that exclusively focused on the description of innovative technological concepts (Table 1, E.2), such as the approaches by Ballagas and Walz (2007), Chen (2009), Diah et al (2010), Ferdinand et al (2005, Mohamudally (2006), Milǒs et al (2009), Moore (2009), Martin-Dorta (2010) or Yiannoutsou (2009. For our purpose, an explanation of the effects in relation to individual gameplay mechanisms was crucial.…”