There's nothing wrong with the game itself, but since the updates you may see a lag. Please follow these steps to fix it:
Step 1: Make sure you are connected to Google Play/Game Center/Facebook (otherwise you will lose your progress in the next steps).
Step 2: If you're on Android, clear the cache of the app. If you're on iOS, delete the app and re-install it.
Step 3: Re-install it and run it. You should see the game working just fine!
If none of that works for you, then please check that you have enough available space on your device. If you are nearing full-capacity, try to make space by deleting unused apps, and see if it helps.