Sure! Here's an example of a simple 3D game implemented as a single HTML file with JavaScript:
In this example, we have a simple game in which the player is represented as a blue square on a canvas. The player's position is updated based on user input (such as touch events), and the game state is updated accordingly. The canvas is cleared on each frame and the player is drawn at its new position.
Keep in mind that this is just a starting point, and you can expand and customize the game as per your requirements, adding more features, graphics, and interactions.