Sure! Here's an example of a simple text-based game that meets your requirements:
To play the game, open the HTML file in a web browser on your smartphone. It will prompt you to enter your character name, choose a weapon (sword, axe, or bow), and select armor (leather, chainmail, or plate). Then, it will display a message telling you that your journey begins and you need to defeat the boss. Finally, it will declare that you have successfully defeated the boss.
Please note that this is a simple text-based game as per your requirements and doesn't feature a 3D open world or pictograms. Implementing a fully 3D game with character customization and an open world would require advanced game development technologies and frameworks beyond the scope of a single HTML file.