Thanks for sharing this!
The unzipping works very well.
However, the following line causes trouble:
Because later on in the game, I need to list all items of a directory, using the following.
var items = 
var dir = Directory.new()
var file = dir.get_next()
if file == "":
But every time get_next() is used, it returns a file name that was inside zip_file, and then the next in that zip_file etc.
Also, things like this don't work anymore:
How can I get Godot to stop looking at that zip_file?