I have yet to play it or any of the other freebies GOG has given away. Actually, that's not entirely true, I have run each of them long enough to know I will never play them again. From my perspective, there's a reason these games are/were free: they just aren't that good.
To be fair, I have to admit I didn't try JA either. But it's one of the last games on GOG I'd be interested in trying, it just doesn't look like my kind of game at all, and besides, this specific one seems to be a multiplayer game only?
"Beneath A Steel Sky" isn't a bad game though if you like adventures. That's actually a nice freebie (but you can get it for free on the ScummVM website, too).
You could get BASS for free years before GOG even existed and I even had it on my Linux machine a long time ago, but I can't stand point n' click adventure games. I really tried to enjoy that one after so many people told me it was awesome, but in the end it wasn't, it was just another really, really
boring adventure game, just like every other one I've been told is "epic" or "awesome" or a "must play". I find those games to be about as much fun as working on a spreadsheet. I really do not understand the fascination with them.