To twist the cube, simply press the mouse button over a cubelet face that belongs to the slice you want to move. Keep the button pressed and drag the mouse in the desired direction. Now release the button. Practice a little with a "clean" cube (pressing "Give up" gives you one). That way it is easier to see the results of your actions. Note: The mouse is not used to drag a cubelet to its destination position, but to enter the direction of a slice movement. This means that you don't have to drag the mouse very far. Just moving it to an adjacent cubelet face is enough.
Moving the whole cube is done in the same way. Just keep the Ctrl-Key pressed at the same time.
The "Scramble" button brings the cube to disorder. This is done by taking a "clean" cube and executing 500 random moves. The moves counter is reset to zero and starts counting.
The "Give up" button gives you a "clean" cube. The current value of the moves counter is discarded and the counter stops counting.
The "Sound" checkbox lets you enable and disable the sound effects.
The moves counter shows you the number of moves done so far. It starts counting when you press "Scramble" and stops when you solve the cube or when you press "Give Up".