In Monster Bubble Shooter, you have control over a cannon at the bottom of the screen. Use your mouse to change the direction of the cannon to shoot out a monster. The color of the next monster ready to be shot out of the cannon is shown underneath it. The goal is to match the color of the monster at the bottom to at least two monsters of the same color at the top of the screen. If you shoot a monster so it touches two other like colored monsters, they disappear and you get points. If you miss, the monster sticks to the other ones at the top and you have to get rid of it before time runs out.