     var health: Double = 1.0
     var textureArray: [SKTexture?]? = nil
     
+    // MARK: Make enemy deteriorate.
     func deteriorate() {
         // If health will pass 1.0, 0.667, 0.334, or 0.0
         if (Int(health*3) > Int(health*2.7)) {

    // MARK: Internal SKNode and texture references
    fileprivate var spinnyNode : SKShapeNode?
    fileprivate var badGuys : SKEmitterNode?
    var enemyList = [SKSpriteNode?](repeating: nil, count: 0)
    let atlas = SKTextureAtlas(named: "Enemy Sprite Atlas")
    
    // MARK: Enemy texture matrix.
    var textureMatrix = [[SKTexture?]](repeating: [SKTexture?](repeating: nil, count: 4), count: 3)
    
    // MARK: Configuration variables.
    let spinnyStuff = UserDefaults.standard.value(forKey: "spinnyStuff") ?? false

    func playerDeter() {
        badGuys?.particleBirthRate *= 0.999
        
        for enemy in enemyArray {
            if enemy!.intersects(badGuys!) {
                badGuys?.particleBirthRate *= 0.999
            }
