Sure, here's an example of a simple generative art game implemented as a single HTML file using JavaScript:
In this game, a canvas element is used to display randomly generated colorful shapes. The `getRandomColor` function generates a random color, and the `generateArt` function generates random squares on the canvas. The game continuously generates art by calling itself using the `requestAnimationFrame` method. The resulting art will keep changing as new shapes are generated.
You can test this game by saving the code in a file with a `.html` extension (e.g., `generative-art-game.html`) and opening it in a web browser. The browser will render the canvas and continuously update the displayed art. You can also customize the size and appearance of the canvas by modifying the `canvas` element's attributes and the `context` properties in the JavaScript code.