Sure! Here's an example of a simple game implemented as a single HTML file using JavaScript. This game is called "DnD at Walmart" and it can be played on a smartphone. The game uses pictograms to represent various elements.
DnD at Walmart
Help the shopper find all the items on their shopping list!
In this game, there is a shopping cart and a few items displayed as pictograms. The goal is to drag and drop the items into the shopping cart. When an item is successfully dropped, it is marked as 'found' and the score increases. The game ends when all items are found. You can replace the placeholder image URLs with your own pictogram images.
Please note that this is a basic example to demonstrate how a game can be implemented using JavaScript in a single HTML file. You can modify and enhance the game logic and design as per your requirements.