Sure! Here's an example of a simple multiplayer game implemented in a single HTML file using JavaScript. The game is called "PictoMatch," and it involves two players trying to match pictograms as quickly as possible.
In this game, two players will see a random pictogram assigned to them, and they need to check if their pictograms match. If there's a match, an alert will be displayed stating that both players win. Otherwise, an alert will notify them to keep playing.
You can further enhance this game by adding user interaction, timers, scoring, and additional game logic as per your requirements.