If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Shoot balls to clear them by forming groups of 3 or more of the same color. Any different colored balls that are hanging on to what you cleared will also fall. Sometimes you may need to shoot the balls against the wall so that they bounce off and hit your target. The game will end if you cannot clear all of the balls before they reach the bottom of the screen.
Shoot balls to clear them before they reach the bottom.