This classic reflection application of the deduction to arrive in less than 10 rounds to guess the sequence of 4 colors and their order.
For each of the 4 boxes, moving a ball of color in the appropriate box, then click OK to get the result. A black peg indicates a correct color but wrong position. A white piece shows good color and good position.
(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.