Understanding players and their game playing behavior is a growing area of research that is currently being explored by many game companies, including Electronic Arts, Hobbo Entertainment, and XEODesign. In this paper, we report on a study we conducted to understand the influence of age, gender, and previous gaming experience on customization activities of game players in the younger age group within games. We note that player behavior in such scenarios can be used to improve game design and maybe lead to new player models. The results show significant differences between genders within our sample and the type of activities and items used within character and level customizations. We also found some correlations between previous gaming experience and strategies users take to customize their levels, as well as the type of customization activities they engage in. These results will be discussed in this paper as they contribute several design lessons for designs of games or virtual worlds that involve customizations.