Protecting the planet from invasion is not your first time, so the plot of the game Planet Defense seems to you too predictable and in vain. A nice green aliens asks you to help him, and looking at his sad face, he can not be denied. For you, the intergalactic war will turn into an exciting game. The planet is about to attack a huge ship round like a plate. It is loaded with multi-colored round objects, similar to balls. The newcomers are going to cover the surface. To prevent this from happening, shoot the balls, if there are three or more identical balls in the row, they will fall without causing harm. At a critical approximation, the atmosphere of the planet will send signals.