With this function, you can replay the game backward or forward till you reach the special point of your interest. After obtaining that point, you may continue playing with new interactions.
Click this button to start an animated replay of the current game in reverse direction. The button is disabled if the undo stack is empty.
Click this button to start an animated replay of the current game in normal direction. The button is disabled if the redo stack is empty.You should also consider the following:
The button is shown blinking as long as an extensive animation is running. If you click this button, the animation will be stopped. The processing will be terminated as soon as a consistent game state is reached. Alternatively, you can press the Esc key.