Here's an example of a simple game implementation in a single HTML file, using JavaScript and enclosed in script tags. Please note that this is just a basic example and does not actually implement the GTA 6 game. It's a simplified game to showcase the structure and concepts.
This code sets up a simple game where you control a player using arrow keys on a smartphone. The player moves around a canvas, and enemies are represented by rectangles. When the player collides with any enemy, a "Game Over!" alert is displayed. This is just a basic structure, and you can modify and enhance it to create a more complex game if needed.