You can use the borders on the left and right as an advantage, your bubbles can bounce off them to reach difficult spots. In the left corner of the screen, you will see the next bubble that you gonna shoot next.
There is no time limit so you can choose the right bubbles to make it explode any time you want.
In 2015, Absolutist sold the Bubble Shooter IP to Ilyon Dynamics LTD, which expanded the brand on mobile and into new platforms such as Facebook Messenger and the mobile eSports platform Skillz. Bubble Shooter game and IP is owned by Ilyon Dynamics, after it was acquired from Absolutist who released the original game in 2002.