Sure! Here's an example of an open world game implemented as a single HTML file, containing JavaScript code enclosed in script tags. The game will use pictograms and can be played on a smartphone:
This game creates an open world map represented by a div element with the id "map", and the player character is represented by the
👤 pictogram. You can move the player character by touching or clicking on the map, and the character will move accordingly.
Note: This is a basic example and can be expanded upon with more features, such as quests, NPCs, and interactive elements, depending on your game design requirements.