Why was the game divided into 2 archives at all? There are games that weigh much more, and are downloaded in one archive. Can someone who has unpacked and plays without any problems pack it into one archive and upload it to pixeldrain or mediafire? This will be much easier than all these explanations on several pages how to unpack, especially since everyone is different archivators, and what works for one may not work for another.
P.S.
Download the archives and save their names and file types as they are, try to unzip them 7zip both at the same time or just the first archive. If you put the second archive in another folder and unzip the first one without it, an error occurs: an unexpected end of the archive. If both archives are in the same folder, there is no such error, which means that the second archive is pulled up automatically. You can check it out for yourself.