Haven't really given it any thought, isn't the installer working?
In any case, you can dl individual files here: https://projectrik.com/install/
And I threw together a .zip of the current version, in other words just the files you'd find in the link above but zipped together..
Note that if you just unzip launching from the website won't work unless you run "riklauncher.exe" once manually from the location you unzip it to. When you do that it updates the registry so chrome/firefox/whatever knows where RIK is "installed".
e: So, yes, there is now a zip file version of the game :p
I suppose zip file is for the paranoid people who are afraid of viruses.