This example presents a mouse-tracking game in which a colored dot follows the cursor as long as it stays inside the visualization area. The game starts only after the user clicks a green "Start" button; once active, moving the cursor outside the defined bounds changes the dot’s color to red, indicating the player is "out." Built with React and D3 v6, the visualization uses React’s `useState` hook to manage game state and cursor position, while SVG rendering with a `VizContainer` component handles the static margins and drawing area. Mouse events (`onMouseMove`, `onMouseLeave`) update the dot’s coordinates, clamped to the inner dimensions.