Sure! Here is a simple 3D battle game implemented as a single HTML file using JavaScript and enclosed in script tags. The game can be played on a smartphone and utilizes pictograms. Note that this is a basic implementation and can be further expanded upon.
To play the game, simply save the above code into an HTML file (e.g., `battle_game.html`) and open it in a web browser that supports JavaScript. The game takes place on a canvas element where you control a blue square player using the arrow keys. The red square enemy will move towards your position, and if they collide, a "Game Over!" alert will be displayed.