Sure! Here's an example of a simple game written in a single HTML file using JavaScript. The game is called "Dance Quest":
In this game, the player controls a female dancer represented by a pink rectangle. The objective is to move the dancer using the arrow keys and reach the center of the canvas (representing the boyfriend) to save him. Once the player reaches the center, a message will be displayed indicating that the boyfriend has been saved.
Note: This is a very basic example of a game, without any animations or intricate gameplay mechanics. Feel free to expand and enhance it according to your game's requirements and preferences.