Sure! Here's an implementation of the game you described using HTML, JavaScript, and pictograms. Please note that due to limitations in the text-based interface, I can only provide you with the code. You would need to copy and save it as an HTML file and then open it in a web browser to play the game.
To play the game, copy the entire code and save it as a .html file (e.g., `game.html`). Then, open the file in a web browser on your smartphone or any other device. You will see a square moving around inside a box. If the square goes outside the box, it will get teleported to a random position inside the box and the background will become slightly darker. Every 5 seconds, the background will darken more, making the game creepier. The square's movement speed is intentionally set to ensure it doesn't move too fast.
Have fun playing the game!