Sure! Here's an example of a simple game implemented in a single HTML file using JavaScript, enclosed in script tags. The game objective is to reach the flag within 30 seconds by using the arrow keys to move up, down, left, or right. The flag will appear randomly in the game box on each play.
To play the game, simply copy the code into an HTML file and open it in a web browser (preferably on a smartphone for easier control with touch). Use the arrow keys to move the blue square (player) up, down, left, or right and try to reach the red square (flag) within 30 seconds.