So, as you're trying to escape, you'll stumble upon all these locked doors and hidden rooms. That's where the Rusty Padlock Key comes in - it's one of the many items you'll need to find to unlock new areas and progress through the game. You'll have to sneak around, hide from granny, and solve puzzles to get your hands on it.
The core loop of the game is all about exploration and stealth. You'll be creeping around, trying not to make a sound, while granny is stalking you through the house. It's super tense and exciting, especially when you barely avoid getting caught!