Available on iOS and Android for free, Geometry Dash World runs on the 2.1 engine. It has fewer levels, but the core physics and gameplay are identical to v21.
Assuming you find a legitimate (non-virus) version of a Geometry Dash 2.1 repack, here is what you typically get: geometry dash v21 repack
Since you are already going the unofficial route, why not enhance the game? Here are the top mods compatible with v2.1 repacks: Available on iOS and Android for free, Geometry
To install these mods, download the .dll files and place them in the GeometryDash/Resources folder, then run the game via Injector.exe (if provided). Custom Song Hack: Remove the "New Grounds" restriction,
If you own Geometry Dash on Steam (it costs $3.99 on sale), you can downgrade to 2.1 using the Steam Console.
The repack was usually a standalone executable or folder. Players did not need Steam running to play it. This made it popular in schools, libraries, and on computers where users did not have administrative rights to install new software.
Fix: This occurs when trying to play online levels from a cracked client. You need a local level server emulator (e.g., "GDShare Server 2.1"). These are often included in the repack’s "Extras" folder.