Sure, here's a simple example of a number guessing game implemented as a single HTML file using JavaScript:
Number Guessing Game
To play the game:
1. Open the HTML file in a web browser.
2. Click on the "Start" button to begin the game.
3. Enter a number in the input field and click on the "Guess" button to make a guess.
4. The game will provide feedback whether the secret number is higher or lower than your guess.
5. Keep making guesses until you correctly guess the secret number.
6. Upon winning, the game will congratulate you and hide the guessing interface.