Sure, I can help you create a simplified version of a FIFA game using JavaScript in a single HTML file. Here's an example implementation:
This code sets up a simple FIFA game where a ball moves around the canvas. It utilizes the `<canvas>` element for drawing and animation. The ball is represented as a small circle using the `drawBall()` function, and its position is updated within the `updateBallPosition()` function based on the `ballSpeedX` and `ballSpeedY` variables. The game loop is implemented using the `requestAnimationFrame()` method.
To play the game, you can copy and paste the above code into a new HTML file, save it with a `.html` extension, and open it in a web browser (preferably on a smartphone for optimal display). The ball will continuously move within the canvas boundaries, bouncing off the walls when it reaches them.
Please note that this is a very basic implementation and does not include advanced gameplay or player interaction found in a full FIFA game. It's just a starting point to demonstrate the concept. Feel free to further enhance it with additional features as per your requirement.