If you're just looking for free animated wallpapers without Wallpaper Engine, try (open source, free on Microsoft Store) or Rainmeter with animated assets.
💡 If you use a repack, you can still find wallpaper files online and drag-and-drop them directly into the interface to use them.
Wallpaper Engine is a popular software that allows users to customize their desktop backgrounds with dynamic and interactive wallpapers. A repack of Wallpaper Engine refers to a modified version of the software that has been re-packaged and re-distributed, often with additional features or tweaks.