In this final article of a three-part series, developers learn how to create a main menu, add sounds, animate buttons, pause and exit the game. They start by creating a new scene for the main menu, adding a background image and a play button that transitions to the game scene when clicked. Next, they animate the play button using Unity's animation tool, adding a scale property and a clicking effect. The developers also add a pause feature, allowing players to pause the game and resume playing. They implement sound effects, including an explosion sound for when frogs die, and create buttons to toggle sound on and off. Finally, they edit scripts to play sounds at the right times, such as when the frog explodes or when the sound button is clicked.