Sure, here's an example of a simple shooting game implemented as a single HTML file using JavaScript and enclosed in script tags:
Score: 0
This game allows the player to shoot bullets by clicking on the game container. The goal is to shoot the randomly appearing targets and earn points. The score is displayed at the top. The player is represented by a red square, bullets are yellow rectangles, and targets are green squares. Feel free to modify and enhance the game as per your requirements.