Sure, here's an example of a simple Pac-Man game implemented as a single HTML file using JavaScript and enclosed in script tags:
In this example, when the HTML document is loaded, it creates a game board div and a Pac-Man div inside it. The Pac-Man div is then assigned a class name and added as a child element of the game board.
The movement of the Pac-Man is handled by the `movePacman` function, which listens for keydown events. When a specific arrow key is pressed, the Pac-Man's position is updated accordingly and its position on the screen is updated by setting its `left` and `top` CSS properties.
Please note that this is a very basic implementation of a Pac-Man game and only handles movement in four directions. It does not include any game logic, scoring, or collision detection. You would need to implement those additional features to create a more complete and functional game.