Can I suggest to get something else entirely?
I recently played Enclave, it's a pretty game but after the 3rd or 4rd mission or so it became more of a grind to finish it. If GOG would only have Blade of Darkness
which is a similar game but so much better.
Don't really know about Advent Rising, could be good and about the cliffhanger ending, Anachronox has that too, but that didn't stop it from being one of the most memorable games I've ever played.
Do you already have Anachronox? If not I would get that instead.
Well severance blade of darkness looks decent, but its not on GOG, so obviously not an option.
I dont have Anachronox, and i've never played it either. Maybe you can fill me in on what is good about it?
Advent Rising. Just. Buy. It. Now.
Especially if you liked Mass Effect. Those games share so much.
I liked Mass Effect 1. It went downhill after that in my opinion.
It seems more people favour Advent Rising over Enclave so far.