Sure! Here's a simple game implemented as a single HTML file in JavaScript:
Find the Star
In this game, a 5x5 grid is displayed on the screen, and the player's objective is to find the star hidden underneath one of the cells. The star's position is randomly generated at the start of each game.
To play the game, simply open the HTML file in a web browser (on a smartphone or computer) and tap/click on the cells to reveal what's underneath. If the player successfully finds the star, an alert will be shown, congratulating them on their victory.