Sure, here's an example of a simple game implemented as a single HTML file using JavaScript and enclosed in script tags:
In this game, a particle is represented by a red circle on a canvas. The particle moves around the canvas, wrapping around the edges when it reaches them. The game continuously updates the particle position and redraws it on the canvas using the `requestAnimationFrame` function.
You can copy this code into an HTML file, open it in a web browser, and interact with the game. The game runs in a loop and the particle will keep moving indefinitely.