On page 115 is this text:
Add a new property named playingLevel to the GameScene class, and give it a default value of false:
var playingLevel = false
Then, at the end of the spawnMultipleGloops() method, set playingLevel to true:
var playingLevel = true
The last line of that is intended to set the class property to true, but instead is redeclaring a new local playingLevel
variable and setting that to true.
The last line should perhaps have been
playingLevel = true