[iOS version]
Playing music on iTunes or other media while playing the game on your device will cause the music or both music and in-game sounds to stop playing. As this also impacts your device's memory usage, please do not run other apps while playing the game.

[Android version]
If you play music while playing the game, the in-game sound may become distorted. Even if the music is playing smoothly, the app may slow down. If this occurs, please stop the music and ensure that only the game is running.