There is no in-game sensitivity slider. Instead, adjust your Windows mouse DPI settings. Lower your mouse polling rate to 125 Hz (if you have a gaming mouse) to prevent erratic slingshot behavior.
Version 6.6.2 sits comfortably within the era where Rovio was experimenting with pop-culture parodies through the "Piggywood Studios" episodes. These levels featured movie-themed posters and elaborate sets, adding a layer of humor and satire that appealed to older players. Angry Birds Seasons 6.6.2 Pc
The search for a native, official Angry Birds Seasons 6.6.2 release specifically for PC reveals that this version number is primarily associated with the Android (APK) There is no in-game sensitivity slider