Sure, here's an example of a simple mobile game implemented as a single HTML file using JavaScript and enclosed in script tags:
This game features a particle bouncing inside the canvas. It creates a circle using the `canvas` element and the `drawParticle` function, which is then updated using the `updateParticle` function. The game loop continuously clears the canvas, redraws the particle, and updates its position using `requestAnimationFrame`. The particle bounces off the edges of the canvas. You can customize the game further by adding additional features, such as user input and scoring mechanisms.