This is typically a reverse-engineered or scratch-built version of the game using JavaScript and the Phaser or PixiJS framework. These versions usually include the first few official levels (Stereo Madness, Back on Track, Polargeist, etc.) but lack the level editor or online features. They are lightweight and run instantly.
I understand you’re looking for a narrative or backstory related to the search phrase — not just a link, but a story .
GitHub hosts Geometry Dash in several forms, ranging from direct browser-based versions to open-source recreation projects: