Sure! Here's a simple example of how you can create a simplified version of Geometry Dash using HTML and JavaScript as a single HTML file:
In this simplified version, you control a red square by tapping/clicking on the screen. The square moves horizontally and you need to avoid collisions with randomly generated obstacles.
Note: This is a very basic example and does not include all the features of the original Geometry Dash game. It's provided just to demonstrate how you can create a simple game using HTML and JavaScript. You can further enhance it by adding more obstacles, levels, scoring, sound effects, etc.