Sure! Here's an example of a simple platformer game implemented as a single HTML file using JavaScript. This game will be playable on smartphones and includes pictograms for visual representation:
In this example, the game consists of a simple platform represented by a colored "ground" element at the bottom of the screen, and a player character represented by a pictogram
👾. The player can be moved horizontally using the left and right arrow keys on a smartphone's keyboard.
You can copy this entire code into a single HTML file, save it, and open it in a web browser on your smartphone to play the game.