Sure! Here's an example of a simple shooting game implemented in a single HTML file using JavaScript and enclosed in script tags:
This game involves controlling a player with arrow keys and shooting bullets with the spacebar to destroy enemies. The goal is to prevent any enemies from reaching the bottom of the canvas. Each bullet that collides with an enemy will remove both from the game. The game will end if any enemy reaches the bottom. The player can move left and right within the canvas boundaries.