Sure! Here's an example of a game implemented as a single HTML file that meets your requirements. In this game, you control a cartoon planet by changing its position to dodge asteroids and redirect them using gravity to attack other planets. The game is designed for smartphone operation and uses pictograms for the visuals.
To play the game, you can open the above code in your browser, which will display a game canvas. Use your smartphone touch controls to move the planet and avoid asteroids. The goal is to collide the asteroids with other tiny planets. You can customize the game further by adding additional features, levels, or graphics as desired.