Sure! Here's a simple fighting game implemented in a single HTML file using JavaScript. The game will be playable on smartphones and uses pictograms for visual representation.
This game features two players represented by colored rectangles on a canvas. Player 1 (blue) can be controlled using the arrow keys, and the Enter key initiates an attack. Player 2 (red) will temporarily change color to black when attacked. The game loop constantly updates and redraws the players on the canvas.
Please note that this is a very basic implementation and can be improved and expanded upon to create a more engaging fighting game.