Sure! Here's an example of a simple game called "Warden Boss Fight" implemented as a single HTML file using JavaScript and enclosed in script tags:
Warden Boss Fight
This game simulates a boss fight with a blind warden. The player's goal is to throw snowballs at the warden to distract him. The player can control their position using the mouse and throw snowballs by clicking on the canvas. The warden moves randomly left and right at the top of the canvas. When a snowball hits the warden, he becomes distracted and turns red.
Note: This is just a basic example to get started. You can further enhance the game mechanics, add levels, add scoring, etc., based on your requirements and preferences.