Hi there :)
As Hildunn stated, you can download and extract the game archive manually through your browser. The Windows / Mac readme's also recommend doing this, as it is probably the easiest way.
That being said, there is also a workaround to guide itch.io past the decompression error. I made a post describing this process about one month ago, it should still be functional:
https://itch.io/post/10403863
Hope that helps!