Sure! Here is an example of an idle game implemented as a single HTML file using JavaScript:
Idle Game
In this game, you have a score that increases whenever you click the "Click" button. You can also buy auto clickers which will automatically increase your score every second, multiplying your score by the current multiplier value. You can increase the multiplier by purchasing it multiple times.
Please copy this code into a new HTML file and open it in a web browser (preferably on a smartphone) to start playing the idle game.