SIMMETRY can not be installed.

Without admin permisions error appears: No enough space which is wrong in my case.
Starting GOG as admin another error appears: installation failed (in German "Installation fehlgeschlagen")

Any help about this?

What helped me out:
I have deleted the download folder of the game. After that the game was downloaded again and installed well.

I wasn't able to install it via GOG Galaxy client, but if you open GOG in your browser, there is an option to download an offline installer.

It's for the up to date version 1.02 and worked fine for me on the first try.
Hope that solves your problem too.