Why don't you simply go to the game's website
and download it from there? It's free of charge and DRM-free too.
I was actually able to download from my Library page through the Offline Backup option, but thats is a good alternative too. Glad to see even though the game (from what I've heard) is no longer worked on by the developers is still available!
As far as I know, the official development team has stopped working on the game more than one year ago and they even closed the game's forum. However the source code is still actively worked on, as you can see here
Unfortunately, finding enough active players could be troublesome.
I suggest you to download the game from its own website, because the GOG version could be outdated.