Sure! Here's an example of a game implemented as a single HTML file, using JavaScript and enclosed in script tags:
The code provided sets up a basic game structure using HTML canvas and JavaScript. You can add your own game elements, such as the protagonist Marvin, dragons, bosses, and dimensions. Implementing 3D graphics and using pictograms would require additional libraries or frameworks, like WebGL or Three.js.
Remember to fill in the game-specific logic into the `update` and `render` functions, which handle game dynamics and drawing on the canvas, respectively.