     
     var gameState: GameState!
     var players = [Int: PlayerSpriteNode]()
-    var obstacles = [Int: SKSpriteNode]()
+    var obstacles = [Int: ObstacleSpriteNode]()
     var environmentNodes = [Int: EnvironmentSpriteNode]()
 
     var initialGhostStore: GhostStore?

        grid.addChild(scoreNode)
    }
    
    // MARK: Rendering

    private func createEnvironmentNode(environment: Environment) -> EnvironmentSpriteNode {
        let environmentSpriteNode = EnvironmentSpriteNode(environment: environment)

    var isMultiplayer = false
    var peers = [MCPeerID]()
    
    
    // ==============================================
    // MARK: Overridden methods
    // ==============================================
    
    override func didMoveToView(view: SKView) {
        initLogicEngine()
