To create a game with the 2D Game Kit, follow these steps:

1. Create a new Unity 2D project.
2. Import 2D Game Kit (free from Unity Technologies) from the Asset Store by following the same steps as in the previous recipe. So first, open the Unity Asset Store in a web browser and log in to your Unity account in the Asset Store.
3. Search for and select the free 2D Game Kit in the Asset Store. Click Add to My Assets, and then, after the button changes, click Open in Unity. Click Download, and when downloaded, click Import. Say Yes to any popup about losing saved work by importing a complete project. 
4. Create a new 2D Game Kit Scene by choosing Kit Tools | Create New Scene. You'll then be asked to name the Scene (enter 2D_gameKit_example) and a new Scene asset file will be created in your Project | Assets folder. You'll see that there are quite a few special GameObjects in the Hierarchy...