Just press the green flag and watch as the days go by. It is meant for you to use it in your games. Look at the notes and credits for more information about that. Tell me in the comments what you make with this.
This was created as a template so feel free to use it in your games. You should be able to very easily change the timing to make the day take longer, or get rid of the ground, or any other changes you need to fit your game.