Sure, here's an example of a simple game implemented as a single HTML file with JavaScript. The game will run on a smartphone and use pictograms:
In this game, there are several pictograms displayed on the screen. The player's goal is to click on each pictogram to make them disappear. Once all the pictograms are hidden, a congratulations message is displayed.
Please note that this is a very basic example, and you can modify or enhance it according to your requirements to create a more complex and engaging game.