Sure! Here's an example of a simple roller coaster game implemented as a single HTML file, using JavaScript and enclosed within script tags:
To play the game, you can open this HTML file in a web browser on your smartphone. The game will display a red "ball" on a canvas, simulating a roller coaster ride. The ball will continuously move and bounce off the walls of the canvas.
Note: This is just a basic example to demonstrate the concept of a roller coaster game. You can expand upon it by adding more features, graphics, and interactivity as per your requirements.