Here's an example of a simple game implemented as a single HTML file using JavaScript and enclosed in script tags. Please note that this is a very basic game and not in any way related to GTA 5.
This is a simple game where you control a rectangular player's movement on a canvas using touch controls (up and down). The objective is to avoid colliding with red obstacles scrolling towards the player. The score increases as the player successfully avoids obstacles. The game ends if the player collides with any obstacle.