Sure! Here's an example of a simple text-based game called "Pizza Tower" implemented as a single HTML file using JavaScript and enclosed in script tags:
The game presents a simple text-based menu to the player on their smartphone. They can choose to order pizza, eat pizza, or exit the game. Depending on the selected option, different messages are displayed to the player.
Note: Since you specifically requested a single HTML file, the game is kept simple and text-based. However, if you wish to implement more complex gameplay with pictograms or interactive graphics, it would be better to separate the HTML, CSS, and JavaScript code into separate files and use appropriate libraries or frameworks for game development.