press the flag twice. The left player can move up with W key and it can move down with S key. The right player can move up with up key and it can move down with down key.
the rule is the same as tie break. First to 7 wins. 球が速いと思う人はこれも遊んで https://scratch.mit.edu/projects/773733485/ If you think the ball speed is too fast, play this game https://scratch.mit.edu/projects/773733485/