To print game over screen, try this in the world:
<< Code Omitted >>
Line 16 will fail if the user is not logged in (as you cannot invoke a method on a null reference, i.e. getUserName on myInfo). Include "&& myInfo != null" on line 14..
Also, line 10 may also fail if storage is not available for any other reason other than the user not being logged in. Enclose the "UserInfo" lines of the method in:
if (UserInfo.isStorageAvailable())
{
...
}
You can add an "else" clause to show "non-UserInfo" game over.