Sure! Here's an example of a simple Pong game implemented as a single HTML file using JavaScript, enclosed in script tags. The game can be played on a smartphone using buttons to move the player's stick, while the opponent's stick is controlled by AI.
To play the game, you can copy the above code into a new HTML file and open it in a web browser on your smartphone. The game uses the up and down arrow buttons to move the player's stick up and down on the screen. The opponent's stick is controlled by an AI that follows the movement of the ball. The score is displayed at the top of the game canvas. Have fun playing Pong!