Sure! Here's a simple implementation of a game similar to Geometry Dash using JavaScript, HTML, and CSS:
When you open this HTML file in a web browser on your smartphone, you'll see a black game area with a white square representing the player. The player moves up and down as obstacles move from right to left. You can tap anywhere on the game area to make the player jump. Your goal is to avoid the red obstacles, and every successful pass through an obstacle will increase your score.
Please note that this is a very basic implementation and doesn't include advanced features like levels, custom levels, or custom characters. It's just a starting point for you to improve upon and make it more similar to Geometry Dash.