There was a game called "Lost Eden", which I used to play regularly on my PC. Although the game was not horrific by any means, it was slightly disturbing. In the second section of the game, Adam was required to visit the Crypts of the Fortress he was born in. An FMV of this crypt revealed a passageway which contained human bodies that had been immersed in concrete. Their 'poses' at time of death were captured for all to see, and they're not very pleasant. The music that accompanied this level was also quite scary.

Reading this post has made me want the game again. I think I'll go and buy it from E-Bay.