Sure, here's an example of a simple game implemented as a single HTML file using JavaScript:
To play the game, simply copy the above code into an HTML file (e.g., `game.html`) and open it in a web browser on your smartphone. The game will present a pictogram in the center of the canvas, and you need to tap/click on it to increase your score and display a new random pictogram. The `pictograms` array can be customized with other pictograms as per your preference.
(Note: This is a basic example and can be further improved with additional features/graphics based on your requirements.)