Sure, here's a simple game implemented as a single HTML file using JavaScript:
This code will create a game where a ball bounces around inside a canvas element. The ball starts at the center and moves in a diagonal direction. Each time it hits the side of the canvas, it bounces back and increases in size and speed. The game is displayed on a smartphone and utilizes the `canvas` tag for drawing graphics.
Please note that the game logic can be further expanded, and additional features such as scoring, levels, or game controls can be added. This is just a basic implementation to meet the provided requirements.