Sure! Here's an example of a simple game called "Jumper Car" that you can play within a single HTML file using JavaScript:
To play the game, simply save the above code in an HTML file and open it in a web browser. The game will run for 30 seconds, and the objective is to avoid the "🚧" obstacles using the "🚗" car by moving it to the left or right with the arrow keys. The score is displayed, and a pop-up alert will appear with the final score once the time runs out.