Hi narnar88,
Thank you for using the Apple Support Communities! I understand you are seeing a different language within Game Center and I'd like to help out.
To gather more information, I have a question. Is your entire Game Center app showing in a different language? Or, have you only noticed the different language when you open your Godfather game (this includes alerts related to the game)?
It sounds like you've confirmed the language and region for your iPhone under Settings > General > Language & Region. If this is accurate, I would like to have you restart your iOS device, to test for the same behavior again: Restart your iPhone, iPad, or iPod touch - Apple Support.
If you need continued support, reach back out with more details, and responses to the questions above.
Regards.