Sure! Here's an example of a simple zombie game implemented as a single HTML file:
This example creates a simple game where a blue player square can be controlled using the mouse. The goal is to avoid the green zombie square as it follows the player around the canvas. The game will run in a smartphone browser and use pictograms (shapes) for the player and zombie. Note that this is just a basic implementation to show the game structure and mechanics, and it can be expanded and improved upon based on your specific requirements.