Sure! Here's a simple implementation of the classic Snake game using JavaScript, enclosed in script tags within a single HTML file. The game is playable on a smartphone and uses pictograms to represent the snake and food.
To play the game, simply copy the above code and save it as an HTML file. Open the file in a web browser on your smartphone or desktop. Use the arrow keys to control the snake and try to eat as much food as possible without colliding with the walls or yourself. Enjoy!