Sure! Here's a basic implementation of a 2D shooting game where you have to kill enemy using JavaScript. The game will be playable as a finished game, and you can operate it on a smartphone. For simplicity, I'll use ASCII characters instead of pictograms.
To play the game, simply save the code in a .html file, open it in a web browser on your smartphone, and use the arrow keys to move the player left and right. Press the spacebar to shoot bullets at the enemy. The game will keep track of your score and display the final score when the enemy reaches the end of the game grid.
Note: The visual representation of player, enemy, and bullet may not be accurately rendered on all devices depending on font support, but the game logic will work correctly. Feel free to replace the Unicode characters with pictograms of your choice if your device supports them.