Sure! Here's an example of a simple game implemented in a single HTML file using JavaScript:
This example creates a simple game where a particle moves around the canvas, bouncing off the walls and changing color. The game is implemented using the `<canvas>` element and JavaScript's `setInterval` function to update the game every 10 milliseconds.
You can copy the code into a single HTML file and open it in a web browser on your smartphone to play the game. The particle will move around the screen, bouncing off the walls and changing color.