To change the language and currency in the WildTangent Games App, click on the "Settings" button in the top right corner. Choose your country and then select from the available languages for that country.
You will need to close and restart the Games Application to apply the new country and language changes.
Also, if you are going to make any purchases online with WildTangent - be sure the computer's country setting matches as well. Otherwise you might get an error message.