The goal of the game logic and fast is to eliminate balls that progress on the spiral before they reach the imp at the end of the spiral. To do this, simply shoot at a group of at least two balls of the same color to eliminate them. Plus you get rid of bullets, the higher your score increases.
Use your mouse to aim in the direction desired positioning of the ball and click to shoot.
(Automatic translation)
A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.