Sure! Here's an example of a simple game implemented in a single HTML file using JavaScript. The game assumes smartphone operation and uses pictograms:
When you open the above code in a web browser, it will display a simple game where you control a player (represented by a red rectangle) using the left and right arrow keys. The goal is to avoid colliding with an enemy (represented by a blue rectangle) moving downwards. The player's score increases over time. If the player collides with the enemy, the game ends and the final score is displayed.