Sure, I can help you with that! Here's a simple RPG game implemented as a single HTML file, using JavaScript and enclosed in script tags:
This game sets up a canvas element where a red square represents the player. You can control the player's movement using the arrow keys on a smartphone's virtual keyboard. The player moves in the chosen direction at a constant speed. The game loop continuously updates the player's position based on the input and renders it on the canvas.
Feel free to enhance this code and add more features to create a fully-fledged RPG game!