We've glanced briefly at the key elements of the Unity interface, but there's no need to stop poking around. Far beyond the scope of this book, there is a wealth of menu options, buttons, and controls that we haven't covered. Why not explore those menus or start randomly clicking on things that you don't yet understand? Now is the time to safely break stuff. You didn't work hard to create the Angry Bots Demo, so why not mess around with it a little bit?
Some of the changes you make to the Demo will "stick", even if you don't explicitly choose to save your changes. Duplicate the entire Angry Bots Demo folder before you go crazy.
Here are some things to try:
Select some of the GameObjects in the Hierarchy panel and move them around in the Scene window using the Scene controls. What happens when you put an airlock in the middle of the sky? Can the player still pass through? What if you put the canisters or the computers over the player's head before the game starts? Do they fall, or do they hover? Can you remove objects to help the player careen off the edge of the balcony? What happens when he does?
Randomly right-click / alternate-click in the three different panels and read through the context menu options to see what you're getting yourself into.
Poke around in the GameObject | Create Other menu. There's a whole list of interesting things that you can add to this scene without even touching a 3D modeling program.
What happens when you delete the lights from the scene? Or the camera? Can you add another camera? More lights? How does that affect the Scene?
Can you move the player to another part of the Demo to change your starting position? Can you replace the audio files to make the gun "moo" whenever you fire it?
Download a picture of kittens from the Internet and see if you can wrap it around a boulder model. Kittens rock! You can pull the kitties into your project using the Assets | Import New Asset option in the menu.