Sure! Here's an example of a simple Attack on Titan 2D game implemented as a single HTML file using JavaScript:
In this game, you control a Titan (represented using a pictogram) using the left and right arrow keys on your smartphone. The objective is to avoid colliding with the top boundary of the game board for as long as possible. If the Titan reaches or collides with the top boundary, the game will end, and an alert will be displayed.
Please note that you will need to replace the `emozi_himawari.png` image URL with an actual image file or pictogram that you would like to use for the Titan representation in the game.
Feel free to modify and enhance this code to fit your requirements and add more gameplay elements!