The instructional effects of customization features in child learning games have rarely been examined. This value-added study addresses the existing gap with regards to user-initiated cosmetic customization of environment elements (i.e., non-avatar customization). Participants (N = 143; M[subscript age] = 9.41) studied a biological topic for about 20 min: either using the experimental version of a learning game with customization features, or from a control version without them. Null results were found as concerns between-group differences: both for motivation-related variables and learning outcome measures. These findings indicate that user-initiated cosmetic customization features can be omitted by game designers, especially in settings where children are assigned specific instructional materials from which to study.