destroy existing bullets and create new fleet bullets empty(create_fleet(ai_settingsscreenshipalienswe've created new functioncheck_bullet_alien_collisions()to look for collisions between bullets and aliensand to respond appropriately if the entire fleet has been destroyed this keeps update_bullets(from growing too long and simplifies further development try it yourse lf - catchcreate game that places character that you can move left and right at the bottom of the screen make ball appear at random position at the top of the screen and fall down the screen at steady rate if your character "catchesthe ball by colliding with itmake the ball disappear make new ball each time your character catches the ball or whenever the ball disappears off the bottom of the screen ending the game what' the fun and challenge in game if you can' loseif the player doesn' shoot down the fleet quickly enoughwe'll have the aliens destroy the ship if they hit it at the same timewe'll limit the number of ships player can use and we'll destroy the ship when an alien reaches the bottom of the screen we'll end the game when the player has used up all their ships detecting alien-ship collisions we'll start by checking for collisions between aliens and the ship so we can respond appropriately when an alien hits it we'll check for alien-ship collisions immediately after updating the position of each aliengame_ functions py def update_aliens(ai_settingsshipaliens)""check if the fleet is at an edgeand then update the postions of all aliens in the fleet ""check_fleet_edges(ai_settingsaliensaliens update( look for alien-ship collisions if pygame sprite spritecollideany(shipaliens)print("ship hit!!!"