It is possible to sign in using Apple ID if you wish. An existing guest game can be linked to an Apple ID or you can begin your game by linking to Apple ID. If you have more than one device using the same Apple ID, you will be able to play across those devices. We recommend reading the FAQ on playing across devices.
Please note that you should still write down your unique numerical User ID for your game because we are not be able to locate data using Apple ID.
To stop using an Apple ID with a game:
You will need to go to your device settings, then select your Apple ID profile. Next you should select "passwords and security" followed by "apps using your apple ID, select Bunny Haven and choose to stop using Apple ID.