Sure, here's an example of a simple game called "Pibby 360" implemented as a single HTML file using JavaScript and enclosed in script tags:
This is a basic game where you control a character named Pibby by using arrow keys or touch events on a smartphone to move it around the canvas. The game handles collision detection with the walls and ensures Pibby does not go out of bounds. The code is enclosed in script tags and can be saved as a single HTML file to be played as a finished game.