Sure! Here's a simple text-based game inspired by Undertale, implemented as a single HTML file using JavaScript. Note that this is a simplified version of the game and does not include any pictograms. You can copy the code below and save it as a .html file to play the game on your smartphone.
Once you save the code as an HTML file, open it on your smartphone using a web browser. You will be prompted to enter your name, and the game will begin. The game involves attacking an enemy by choosing the "attack" option or running away by choosing the "run" option. The game will continue until either the enemy or the player has been defeated.