Shibuya et al. (2016)

Shibuya, A.(渋谷明子), Teramoto, M.(寺本水羽), & Shoun, A.(祥雲暁代) (2016).
Toward Individualistic Cooperative Play: A Systematic Analysis of Mobile Social Games in Japan.
In Dal Yong Jin (ed). Mobile Gaming in Asia: Politics, Culture and Emerging Technologies (Part of the series Mobile Communication in Asia: Local Insights, Global Implications). pp 207-225.
ISBN: 978-94-024-0824-9 (Print) 978-94-024-0826-3 (Online) 
This study examines the social features of the 31 most popular games in Japan’s rapidly expanding mobile social game market, as ranked through a survey of 2660 teenagers and young adults in November 2013. Results showed that all 31 games had at least one of the three social features, namely, connections to social networking services (SNSs), competition, and cooperation. In the games, SNS connections were present in 84 % of games, competition in 87 % of games, cooperation in 94 %. Among the cooperative features, individualistic cooperative play was more prevalent than team play. Keywords:Smartphones Social features Social games Systematic analysis Mobile device.