Sure! Here's a simple shooting game implemented as a single HTML file using JavaScript and enclosed in script tags:
This game will display a game container with a green player at the bottom. Players can control the player's position by dragging their finger on the smartphone screen. They can also tap to shoot bullets from the player's position. The bullets will move upwards, and once they go off the screen, they will be removed.
Please note that this is a very basic example and can be further enhanced with game logic, enemy objects, scoring points, sound effects, etc. But I hope this provides a starting point for a simple shooting game!