Sure! Here's a simple side-scroller game implemented as a single HTML file using JavaScript. This example uses pictograms for simplicity:
In this game, you control a player represented by a pictogram (player.png) using the arrow keys on your smartphone. The player can move up and down within the game area. The game area is a fixed size of 500px width and 300px height.
Please note that this is a basic implementation, and you can expand it further by adding obstacles, scoring, and other game mechanics depending on your requirements.