     }
    
     override func update(currentTime: CFTimeInterval) {
+        if finished {
+            return
+        }
         updateBullets()
+        updateEnemies()
+        checkForNextLevel()
     }
     
     private func updateBullets() {

        }
    }
    
    
}

        playerBullets.removeChildrenInArray(bulletsToRemove)
    }
    
    private func updateEnemies() {
        var enemiesToRemove:[EnemyNode] = []
        for node in enemies.children as! [EnemyNode] {
            if !CGRectContainsPoint(frame, node.position) {
                // Mark enemy for removal
                enemiesToRemove.append(node)
                continue
            }
        }
        
        enemies.removeChildrenInArray(enemiesToRemove)
    }
    
    // Spawn a sequence of enemies
    private func spawnEnemies() {
        let count = UInt(log(Float(levelNumber))) + levelNumber
