Hey there! If you're stuck at the loading screen, I am sorry for the issue you're facing. Our team is currently investigating this issue. We recommend that you do not uninstall/reinstall the game as it may wipe your data locally. So if you haven't linked your account to Game Center or Google Play, you may lose your progress forever and we won't be able to recover it for you.
For users who do have their progress uploaded to Game Center or Google Play, please submit a request to our team with the following information:
1) Are you using iOS or Android?
2) Are you linked to Game Center (iOS) or Google Play (Android)
3) Can you provide us with your Game Center or Google Play ID?
We can forward this to the developers and hopefully they'll be able to help you out sooner!