If you're seeing a message each time you launch your game that isn't familiar, it is likely a name generated by Game Center, this can easily be changed within your device Settings app.
- From your device’s Home screen, open your Settings app (gear icon)
- Scroll down to select 'Game Center'
- On the next screen you will be able to make changes where it says your nickname under "Game Center Profile."
Apple Support Article: Using Game Center
If you would like to turn this notification off altogether, this can also be done in your Settings app. Please note: by turning off Game Center, your statistic and scoring information will not be saved and cannot be transferred to a new device.
1. From your device’s Home screen, open your Settings app (gear icon)
2. Scroll down to select 'Game Center'
3. At the bottom of this page, select 'Sign Out'
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