Sure, here's an example of a simple game implemented as a single HTML file using JavaScript. The game is a guessing game where the player tries to guess a secret code. Pictograms are used to represent the numbers in the code. Secret messages are scattered around the screen, and the player can find and decipher them for hints.
Hint: Look for secret messages hidden around the screen!
You can save the above code into a single HTML file (e.g., `game.html`) and open it in a web browser to play the game. The game displays a secret code made up of three pictograms and allows the player to enter their guesses using a numeric input field. After each guess, hints and secret messages are displayed to assist the player in cracking the code. Once the correct code is entered, a congratulatory message is shown.