To install: download all the files on a PC, unzip with 7zip (or another of your liking), copy the extracted file to your phone, and run to install the app.
As far as I know, it works on smartphones with 6GB RAM, I tried on one with 2GB, and it didn't work.
You need to extract the files to be able to play. You can extract the files with Google Files, a pre-installed app, usually named "Files" or "My Files".
The APK file is inside the ZIP, that's why you need to extract it. If Google Files didn't work to extract it, there should be others in the Play Store that work just like it.
