at the beginningyou want to set baddies to an empty list the baddies variable is list of dictionary objects with the following keys'rectthe rect object that describes where and what size the baddie is 'speedhow fast the baddie falls down the screen this integer represents pixels per iteration through the game loop 'surfacethe surface object that has the scaled baddie image drawn on it this is the surface object that is blitted to the surface object returned by pygame display set_mode(line resets the player' score to playerrect topleft (windowwidth windowheight the starting location of the player is in the center of the screen and pixels up from the bottom the first item in line ' tuple is the -coordinate of the left edge the second item in the tuple is the -coordinate of the top edge moveleft moveright moveup movedown false reversecheat slowcheat false baddieaddcounter the movement variables moveleftmoverightmoveupand movedown are set to false the reversecheat and slowcheat variables are also set to false they will be set to true only when the player enables these cheats by holding down the "zand "xkeysrespectively the baddieaddcounter variable is counter to tell the program when to add new baddie at the top of the screen the value in baddieaddcounter increments by one each time the game loop iterates when baddieaddcounter is equal to addnewbaddieratethen the baddieaddcounter counter resets to and new baddie is added to the top of the screen (this check is done later on line pygame mixer music play(- the background music starts playing on line with call to pygame mixer music play(the first argument is the number of times the music should repeat itself - is special value that tells pygame you want the music to repeat endlessly the second argument is float that says how many seconds into the music you want it to start playing passing means the music starts playing from the beginning post questions to