Although a significant proportion of the mobile apps are games there has been little attention paid to their specific characteristics with respect to communication energy. In this paper we select 20 mobile games among the top 100 free Android games, and study their data patterns and communication energy use over a total of 25 hours of playing. The analysis of the energy for communication over 3G networks indicates that there is a wide variation among the games, the largest footprint being 8 times higher than the lowest one. The results also indicates both app-specific and categoryspecific relations between data pattern and energy use, as well as variations in CPU utilisation. Categories and Subject Descriptors C.2.1 [Computer Communication Networks]: Wireless communication; C.4 [Performance of Systems]: Measurement techniques General Terms Design, Measurement Keywords mobile games; communication energy; 3G; Android;