How about all the old SSi games , which later became part of Mindscape then Ubisoft.
and all of the other great war games as well.
I still have my original copy of SSI Cyclones (came on a CD), so if GoG wants to make a deal I'll be more than happy to.
This FPS game introduced me to techno music (by the Power of Se7en), 3D environments, FMV, multi-level gameplay, video games' first 3D Map that you can selectively show portions, and just the visceral scifi experience was awesome. Battle was difficult, with the constant reminder that ammunition comes in short supply. Weapons seemed just right in damage, aside from one weapon at end of the game which vaporizes enemies like a Romulan phaser.
Breathtaking is the best word for it. The music is just AWESOME, and fit the atmosphere *perfectly,* especially the secret level(s)
The FMV was hilarious at times like when [you] the protagonist would be caught peeking at the young blonde's legs . Great acting too by all 3 you can see The ending was heartbreaking for me though.
The storyline I believed was excellent, and every mission made perfect sense and felt like they amounted to something greater. Also at every few mission completes you get a rendered cutscene of your success. If you fail, the screen goes out like what the Terminator would see, given you are a Cyborg.
I believe GoG would find a great opportunity in getting this game in their list, as truly one of the greats.