You must hit the ball when it is on your player. Your player is the yellow LED that is close to your button. You hit the ball by pressing your button.
Game speed increases with every hit. If you miss, the ball goes in your goal and other player gets one point. Your goal is the red LED behind your player. If you press your button when the ball isn't on your player, the other player gets one point.
A round ends when a player gets a point. After a round's end, score info is displayed on the LEDs for three seconds. The player LED of the player who got the point is turned on and the three green LEDs next to each player show the score of the player. Game speed is reset.
When a player reaches three points, the game ends. The five LEDs on the winning player's side are flashed for a few seconds and a new game starts.
I know there are similar projects but I think the code turned out to be pretty clean and very beginner friendly. Instructions are in the code as comments