Hi,
By default both PC and Android builds are compressed to a .zip file format - you simply have to unzip it first and then install the game.
In Android's case, Files by Google should be able to handle .zip files, if that doesnt work, then I suggest redownloading the file, installing RAR apk by win.rar gmbh (found on play store), unzipping/extracting the APK file and then tapping it to install/update the game - that should do the trick.
Cheers