Sure! Here's an example of an open-world game implemented as a single HTML file using JavaScript and enclosed in script tags:
This code sets up a basic open-world game where the player can move around using the arrow keys on a smartphone. The player is represented as a rectangle on the game canvas, and their position is continuously updated based on user input. The game loop handles updating and redrawing the game world each frame.
Feel free to modify and expand on this code to create your own open-world game!