 Now you're going to start creating your own video game. As with most video games, you won't have to start from scratch. You'll be building your game on top of some existing code called an engine, which will take care of a lot of the heavy lifting for you. Most modern video games are also built on engines, which allow the programmers to build better games faster. You'll be writing the logic that controls how all of the characters in your game look, move, and interact with each other. And the game engine will take care of displaying your creation on screen, animating your characters, and keeping track of your score. In the first stage, you're going to modify the variables in the game by substituting your own title, background, and images for your sprites. Just click Edit to edit the variable, then Save and Close to save your modification, and finally hit Run to see your new game in action. If something doesn't look like what you expected, try troubleshooting your game. Troubleshooting, also known as debugging, is when a programmer systematically examines the code to determine the source of the unexpected results. You can troubleshoot your game by opening the function of the variable that didn't do what you wanted it to do. Check. Did you modify the variable correctly? Have fun changing the variables of your big game.