Sure, I can help you with that! Here's an example of a simple generative art game implemented as a single HTML file using JavaScript:
In this game, you can tap/press and drag your finger/mouse on the canvas to create colorful circles. Each circle is randomly colored using RGB values to create a generative art effect. The circles will be drawn as long as you keep your finger/mouse pressed down.
Feel free to modify and customize the code to suit your specific game requirements and add more gameplay elements.