Here's an example of a game implemented in a single HTML file using JavaScript. This game will display random emojis and move them around within a specified box every 0.1 second. You can play the game by trying to catch or click on the emojis as they appear and move.
To play the game, simply open the HTML file in a web browser on your smartphone. Emojis will appear and move randomly within the box, and you can try to catch or click on them. Feel free to customize the game's appearance and rules according to your preferences.