fleet_direction of represents right- represents left self fleet_direction this method sets the initial values for the shipbulletand alien speeds we'll increase these speeds as the player progresses in the game and reset them each time the player starts new game we include fleet_direction in this method so the aliens always move right at the beginning of new game to increase the speeds of the shipbulletsand aliens each time the player reaches new leveluse increase_speed()settings py def increase_speed(self)"""increase speed settings ""self ship_speed_factor *self speedup_scale self bullet_speed_factor *self speedup_scale self alien_speed_factor *self speedup_scale to increase the speed of these game elementswe multiply each speed setting by the value of speedup_scale we increase the game' tempo by calling increase_speed(in check_ bullet_alien_collisions(when the last alien in fleet has been shot down but before creating new fleetgame_ functions py def check_bullet_alien_collisions(ai_settingsscreenshipaliensbullets)--snip-if len(aliens= destroy existing bulletsspeed up gameand create new fleet bullets empty(ai_settings increase_speed(create_fleet(ai_settingsscreenshipalienschanging the values of the speed settings ship_speed_factoralien_speed_ factorand bullet_speed_factor is enough to speed up the entire gameresetting the speed we need to return any changed settings to their initial values each time the player starts new gameor each new game would start with the increased speed settings of the previous gamegame_ functions py def check_play_button(ai_settingsscreenstatsplay_buttonshipaliensbulletsmouse_xmouse_y)"""start new game when the player clicks play ""button_clicked play_button rect collidepoint(mouse_xmouse_yif button_clicked and not stats game_activereset the game settings ai_settings initialize_dynamic_settings(hide the mouse cursor pygame mouse set_visible(false--snip-