A brief guide on how to open these archived world files;
A piece of software that allows you to open archived/zipped files (like WinRAR or 7Zip)
How to view these world files?
1. Download the file using the link below
2. Open the archived file using WinRAR or 7Zip
3. Then open the file that is inside that one (Opening this file might take a while since it needs to decompress all of these files)
4. Once you've opened this file you'll a folder named "world"
5. Move this file into the "saves" folder in your Minecraft root folder (to access your Minecraft root folder on Windows, see the instructions below)
5.1. Press Windows Key + "R"
5.2. Enter the following text in the window that opens "%appdata%/.minecraft" (this is the default location where minecraft gets installed. If you installed it elsewhere this will be different)
6. Launch your game and explore the world you've known so well
If you get a message stating that a download limit has been reached, you'll have to wait 24 hours. After that amount of time you should be able to download it again.