If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
The starting player throws a small white jack. The jack must exceed the dotted line, Once the jack is successfully thrown, the same player throws 2 consecutive bowls. When thrown, the opposition throws 2 bowls. The aim of the game is to get your bowls closer to the jack than the opposition.
Arrow Keys - Aim.
Spacebar - Throw.