I've left a comment on GitHub, but I'll post it here too:
I have the performance issues on my game and it appears to be something to do with SimpleAudioEngine?
My game makes a sound every time you tap the screen. When tapping the screen on an Android 6 device, the game stutters quite badly. I found that disabling the sound effects (but leaving the background music playing) stops all stuttering and the game runs at a smooth 60fps.
Device: Elephone P9000
The game works fine on my Android 5.1 Amazon Fire tablet, which is a much lower spec device.