Sure, here's a simple shooting game implemented as a single HTML file using JavaScript:
This is a basic shooting game where the player controls a character using touch input. The player can move left and right, and shoot bullets by tapping on the screen. The goal is to shoot down enemies that spawn randomly while avoiding collision with them. The game keeps track of the score and displays it on the screen. When the player collides with an enemy, the game ends and shows the final score.