I believe most of the children there play a form of soccer. I believe that duck duck goose is perhaps a form of a german game so if you have small children then this might be a great game to play.
Depending on the age groups children have access to the internet and television. Right now the most sought of toy is the ZHU ZHU PETS which are for age 4+
Well germany is essentially like America, they are quite modernized, therefore it is safe to assume that children play Xbox's and Playstations as well.