Creating a fully functional game like GTA 5 with advanced graphics and mechanics is beyond the scope of a simple HTML-based programming exercise. However, I can provide you with a basic example of a game implemented as a single HTML file using JavaScript. Please keep in mind that this will be a very simple game and will not resemble GTA 5 in any way. Here's an example:
The above code sets up a basic canvas element and creates a square player object. It also adds touch controls for smartphone operation, allowing the player to move the square around the canvas. The game loop updates the game state and redraws the canvas continuously.
Please note that this is a very basic example and does not include any game features or mechanics. Implementing a complete game like GTA 5 would involve much more complex code and assets.