Ensuring that your progress has been saved is important if you've just started the game. To make sure your game gets saved, you'll need to link your guest account to an email address, Game Center, or Facebook.

Linking your account to an email address

The game will link your account immediately. 

Linking your account to Facebook

The game will link your account immediately. 

Linking your account to Game Center

If you haven't used the selected Game Center account with the game before, the linking process will take place immediately.