As an AI language model, I can provide you with a simple example of how you can create a basic Sonic the Hedgehog game using JavaScript within a single HTML file. Please note that this implementation will not be the complete game, but rather a starting point for further development. Here's an example code snippet to get you started:
To use this example, you can create a new HTML file and save the code provided into it. Ensure that you have an image file called `emozi_cat.png` in the same folder as the HTML file. This image should contain different frames of Sonic's animation. When you run the HTML file in a web browser, you will see a simple representation of Sonic, and you can use the arrow keys on your keyboard to move him around the game area.
Please note that this is a basic implementation and does not include advanced game mechanics, levels, or other elements typically found in a complete Sonic the Hedgehog game. However, you can use this as a starting point to build upon and add more features to create your own game.