Sure, here's a simple game using movable blocks implemented as a single HTML file:
In this game, there are two movable blocks represented by `<div>` elements with the "block" class. These blocks are initially positioned at the top-left corner of the screen and have a red background color.
You can touch and drag the blocks on a smartphone screen. The JavaScript code uses touch event listeners to handle mousedown and mousemove events. When you touch an individual block, it calculates the initial touch position relative to the block's current position. As you continue to move your finger, the block's position is updated accordingly.
Note: The game is interactive and can be played as a finished game, allowing you to move the blocks using touch gestures on a smartphone screen.