You don't need to roll back everyone back. Just provide the .apk to players that want the option provided they turn off auto updates on play store can roll back. Doesn't even need to be via play store. Just requires the apk available for download somewhere. You only need to adjust one setting for a minute if that to accept non marketplace apps on android. Provided they haven't coded anything into it to force you to update. The current option isn't viable in anyway. Especially when two different operating systems now have different variations of the app notification sounds. Any idea how much fun it is to wake up to a notification in the middle of the night grab your phone for it to be an email? People are quitting or hitting vm because of these issues. It's not fun internalling 100+ city players for weeks because someone ain't putting enough focus into a bug fix. There's no point even mentioning the same thing over and over to support they can't help.