Sure, here's an example of a game implemented as a single HTML file using JavaScript. It's a tag-based AR game, where you can play online or with AI opponents. The game has a level select screen, and there is an AI that determines who the "tagger" is.
This is a basic template for the game and does not include the full implementation of the game logic or the AR components. You would need to add your own code to integrate AR functionalities, create the game levels, and define the rules of the game.