             }))
         }
     }
+    
+    // MARK: - DID BEGIN CONTACT
     
     func didBeginContact(contact: SKPhysicsContact) {
         let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask

        self.hero.physicsBody?.dynamic = true
        self.hero.physicsBody?.allowsRotation = false
        self.hero.physicsBody?.categoryBitMask = UInt32(self.heroCategory)
        self.hero.physicsBody?.contactTestBitMask = UInt32(self.heroCategory) | UInt32(self.groundCategory) | UInt32(self.obstacleCategory)
        self.addChild(hero)
        
        // Ground [Kevin/Tina]

        addChild(coin)
    }
    
    // MARK: - MENU SCREENS
    // [Sam]
    
    func playBackgroundMusic(filename: String) {
