If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Now you see, the idea of the game is to score as many free-kicks in a row as you can. The more you score, the harder the game will get. Simple! See how many you can score in a row, and then challenge your chums to beat your score. In order to score a goal you will need to set the pitch, power, swerve and direction of the shot.