Sure, here's an example of a simple game implemented as a single HTML file using JavaScript and enclosed in script tags:
This game creates particles represented as simple black circles that move around the canvas. The number of particles and their movement speed can be configured using constants at the beginning of the script. The game updates and renders at 60 frames per second.
To play the game, simply save this code as an HTML file and open it in a web browser that supports JavaScript. The particles will start moving around the screen, creating a simple interactive experience.