Found the comment:-
"The linux package is currently broken, but easily fixable. There's several files in the zip with a prefix of "assets\", creating an assets subdirectory and moving those files into it and deleting the prefix allows the game to launch fine. I think this is just a typo from making the package on windows, as it uses \ for its directories while Unix uses /."
Looks like i'm still making the same mistake with current Linux zip. I'll see if i can correct that for future uploads, but at least you should be able to get things working with this info.
Nick