Actions are one of the ways to add life to your game and make things interactive. Actions allow you to perform different things such as moving, rotating, or scaling nodes, playing sounds, and even running your custom code. When the scene processes its nodes, actions that are linked to these nodes are executed.
To create a node, you run a class method on an action that you need, set its properties, and call the
runAction: method on your node with action as a parameter.
You may find some actions in the
touchesBegan: method in
ERGMyScene.m. In this method, you can see that a new node (of the type
SKSpriteNode) is created, and then a new action is created and attached to it. This action is embedded into another action that makes it repeat forever, ...