Sure! Here's a sample shooting game implemented as a single HTML file using JavaScript:
To play the game on a smartphone, open the HTML file in a browser on your smartphone and control the player by tapping on the screen. Whenever you tap the screen, a bullet will be fired upwards from the player's position. The objective is to hit targets, which you can extend by adding additional object(s) with their own properties and behaviors.
Please note that this is a basic implementation and can be expanded upon to add more features and complexity to the game.