Sure! Here's a simple shooting game implemented as a single HTML file using JavaScript:
Score: 0
To play the game, open the HTML file in a browser (preferably on a smartphone). The player can move left and right using the left and right arrow keys. To shoot, press the spacebar. The goal is to shoot down the falling enemies without colliding with them. The score is displayed at the top right corner of the screen, and the game ends when the player collides with an enemy.