do so, you have to shoot other colorful bubbles at them to make them pop. You can store two bubbles in the cannon and change between them according to your needs.
To shoot your plasma balls and get rid of as many as possible, you have to aim carefully, since a bad shot can block future shots. To aim, tap on the screen and slide your finger to move the trajectory. Thanks to this line, you'll always know where your bubble is headed. You can also make it bounce off walls to get through narrow spaces.
On the bottom of the screen, there are three types of help you can use when you get stuck. The bubbles constantly advance towards you, so your mission is to get rid of them before that happens. Use little boosts to avoid catastrophe and get rid of the plasma before it's too late.