Kaplau93: I have never played any of these games before and only watched a video or two about Ultima Underworld.
I do know that these were very significant computer game releases!
Good thing this is happening during the sale, I just picked up all of the about-to-be delisted games for under $5 now.
Derpowitz: I've heard that back in the day the Ultima Underworld backend was considered a legit competitor to id Software's DOOM engine, but it just didn't get as much marketing.
The game influended ID Software specially in the technical aspects. Apparently Carmack saw the demo in a convention around 1990 and he said that he was able to create a faster texture mapper. Also it is said that Paul Neurath and Romero had some kind of telephone conversations about the concept in 1991. Nothing deep though.
Technologically Ultima Underworld wasn't any joke for that time. And as a finished game and a simulation it is one of the most immersive games ever. I always saw it like the granddaddy of games like Deus Ex, Bioshock, and of course both System Shock games. In fact The original System Shock used a newer version of the Engine.