Sure, here's an example of an endless cube runner game implemented in a single HTML file using JavaScript:
To run the game, you can simply copy and paste the code into a text editor and save it with a .html extension. Then open the file in any web browser (preferably on a smartphone) to play the game. The player can jump by tapping on the screen and the goal is to avoid colliding with the blue obstacles. The score increases as the player successfully avoids obstacles, and the game continues until a collision occurs. When the game ends, an alert will display the player's final score, and the page can be reloaded to play again.