Greetings!

Thanks for submitting your report. Have you tried restarting the game?  Sometimes doing so can help improve performance or solve other minor issues (such as graphical glitches). 
In order to restart the game:

Double-tap your home button
Swipe the app upwards 
Launch the game by tapping on the App icon

This should help. If the problems persist, feel free to get back to me. I'm happy to help. 

Very best,