Set the speed to around 100 for normal playing. Make sure to have your sound on for sound effects but not loud if you are wearing earbuds/headphones, or else your ears will probably die. The point of the game is to catch the mouse, but honestly trying to run away from the mouse is more fun and harder, especially if you make the mouse fast like 40 and the cat at only like 10.
Thanks to Ruhee for being my test subject lol.