So, from moment to moment, you're trying to avoid Granny, who's basically a psychotic old lady trying to kill you. You sneak around, hide in closets, and slowly open doors, hoping she won't hear you. It's super tense and you never know when she'll appear out of nowhere.
The handwheel is this thing that helps you sneak past Granny without making a sound. You use it to unlock doors and escape from rooms, all while trying not to make a peep. It's so satisfying when you manage to sneak past her without getting caught.
