Sure, I can help you create a simple game implemented as a single HTML file using JavaScript. Here's an example of a game where you control a character called "Choo Choo Charles" on a train track:
In this game, you can control the character by touching and dragging it along the train track to move left and right. The character is represented by a blue rectangle.
Please note that this is a basic example and you can expand upon it by adding more functionality, levels, or additional game elements as per your requirements.