I am having an issue. The game loads fine, I load my old game from when I played on steam and I get no mouse up/down movement at all. It's like I am playing the original Wolfenstein3D. I tried making a new game and deleting everything in the save directory and the same thing happens. The game is unplayable at the moment for me.

Edit:

It's completely broken compared to the steam version. I just reinstalled it on steam just to make sure and everything works fine there, but not on the GoG version. I have no sound on the GoG version also and something is wrong with the graphics also. The Save Games have no image thumbnail of where you are at. It's just black.

Edit2:

Tracked down the problem. Seems it is not liking one of my SSD drives. Going to give it a try on another and if not I know the steam version worked fine on my non SSD regular HDD. It might be a problem with it and hardlinked drives. The SSDs I install for games are not mounted in their own drive letter, but as hard linked folders on my game drives. So far I haven't had any issues with this setup till now with Prey. I confirmed the problem once I moved my steam install to the same SSD that GoG one was installed in and the same problem happened. Will update again once I finish the install.

Edit 3: (solved)

So it was the SSD drive that was the problem, not the hardlink. It just does not like the drive. It is a server pull drive a Fusion I/O 3TB SSD that goes in a PCI slot. So it will be rare for too many people to have it. Still it's the first game I ran into that had an issue with it.