it' deeply satisfying to watch others play game you wroteand writing simple game will help you understand how professional games are written as you work through this enter and run the code to understand how each block of code contributes to overall gameplay experiment with different values and settings to gain better understanding of how to refine interactions in your own games note alien invasion will span number of different filesso make new folder on your system called alien_invasion be sure to save all files for the project to this folder so your import statements will work correctly planning your project when building large projectit' important to prepare plan before you begin to write your code your plan will keep you focused and make it more likely that you'll complete the project let' write description of the overall gameplay although this description doesn' cover every detail of alien invasionit provides clear idea of how to start building the gamein alien invasionthe player controls ship that appears at the bottom center of the screen the player can move the ship right and left using the arrow keys and shoot bullets using the spacebar when the game beginsa fleet of aliens fills the sky and moves across and down the screen the player shoots and destroys the aliens if the player shoots all the aliensa new fleet appears that moves faster than the previous fleet if any alien hits the player' ship or reaches the bottom of the screenthe player loses ship if the player loses three shipsthe game ends for the first phase of developmentwe'll make ship that can move right and left the ship should be able to fire bullets when the player presses the spacebar after setting up this behaviorwe can turn our attention to the aliens and refine the gameplay installing pygame before you begin codinginstall pygame here' how to do so on linuxos xand microsoft windows if you're using python on linux or if you're using os xyou'll need to use pip to install pygame pip is program that handles the downloading and installing of python packages for you the following sections will show you how to install packages with pip if you're using python on linux or if you're using windowsyou won' need pip to install pygame insteadmove on to "installing pygame on linuxon page or "installing pygame on windowson page