as you are not on a timer. using the mouse, aim your arrow toward the bubbles at the top of the screen. what you want to do is find groups of bubbles at the top that have the same color as the bubble you are about to shoot.
for example, suppose the bubble at the base of your arrow is purple. look at the top of the screen for groups of purple bubbles that you can hit with your bubble. aim and click, it's pretty simple.
the point of this bubble breaker game is to make the bubbles disappear faster than new ones appear. new rows of bubbles appear whenever the counter 