I remember BioForge, it had alot of atmosphere, but was over a bit fast if I remember. Going way way back, one of my all time favorites was Alternate Reality: The City. An RPG that would have modular sequals that added to the existing content. They eventualy came out with Alternate Reality: The Dungeon which was all the underground content, then I think they ran out of money or something. It used special Atari 800 / 400 coding to give it more colors then was normaly possible at the time so it looked incredible on an Atari but the ports to other computers looked terrible.
This game sounds interesting. If it does well I'm sure it will pave the way to a System Shock 3 down the road.