There is a genre of web games called ‘idle’ or ‘clicker’ type games; Cookie Clicker is one of the most influential, but there are many, many others. These games can be made entirely using HTML/CSS/JS, without a server side aspect.
As part of that, I provided an example game so that they could see how specific game mechanics work – autoclickers, save functionality, buttons, etc. This game is now available on GitHub, if anyone else would like to use it as a base for their game.
You can view the code for the game on GitHub, here.
You can view the playable version of the game online here. It’s certainly not complete, but provides a starting point for someone to build their own clicker game. Enjoy!