Sure! Here's a simple implementation of a billiards game as a single HTML file using JavaScript:
This implementation uses the HTML `<canvas>` element to draw the balls and JavaScript to update their positions and handle collisions with the canvas boundaries. You can play the game by opening the HTML file in a web browser, and the balls will move around the canvas, bouncing off the edges.
Please note that the example above is a simplified implementation and doesn't include advanced features like user interactions or scoring. It can serve as a starting point for developing a more complex billiards game.