Sure! Here's a simple shooting game implemented in a single HTML file using JavaScript. It's designed for smartphone operation and uses pictograms to represent the gameplay elements.
To play the game on a smartphone, you can open the HTML file in a web browser, and it will run the shooting game. You can control the player by dragging your finger on the screen, and bullets are shot when you tap anywhere on the screen. The objective is to shoot the bullets before they reach the top of the canvas.
I hope this meets your requirements for a shooting game implemented in a single HTML file using JavaScript, enclosed in script tags, and playable as a finished game. Enjoy!