(1) They laughed at the monkey because it had taken their ball. After a few minutes, the monkey joined (in) the game.
(2) Its action was funny. They laughed at the monkey. Then it took the football and gave it to Peter. It joined them in the football game. It was an unforgettable day.
(3) They laughed at the monkey after it took / had taken the ball. Then it joined them in the football game. After that they continued playing happily.
(4) They laughed at the monkey. It did many funny things to them. They wanted to take the ball (back), but it did not give it to them. So they let it join (in) their game.
(5) They laughed at the monkey. It had taken away their (foot)ball. They got upset because they could not continue the game.