Adjusting game speed

At the lower left of the overlay you will find a selector with three icons. The left-most option will set the speed to 0.5x, which is half speed. The middle icon will set the game speed to normal, and the right-hand icon will speed up gameplay to the selected fast-forward speed (default 2x).

If you would like to change your fast-forward speed, you can find the options for that on the Config tab of the Saves & Settings menu.