Sure! Here's a simple game implemented as a single HTML file using JavaScript:
Copy the above code and save it as a `.html` file. When you open the file in a web browser, you will see a game screen with an input field and a submit button. The player needs to enter the correct code ("7777") and click the submit button.
If the player enters the correct code, a success message will be displayed stating they saved the world. If the player enters the wrong code, a failure message will be displayed informing them that their house has been nuked.
Please note that this is a very basic example just to demonstrate the game mechanics. You can customize the design, add more features, and improve the gameplay as per your requirements.