Sure! Here's an example of a simple math game implemented as a single HTML file:
👋🔲
You can copy and paste the above code into a text file, save it with a `.html` extension, and then open it in your smartphone's web browser. When you click on the black emoji character, the game will start. It will show you three difficulty buttons, and then display a series of math questions. If you answer all the questions correctly, you win; otherwise, you will be jump scared (represented by the emoji character changing to
😱).