Yes this would have been mind-blowing.

Ps there was a game that had a similar FPS view in those days. It was a maze game with polygon graphics but no textures. I forget the name. No shooting though!

* Mercenary: Escape from Targ (Novagen) http://mercenarysite.free.fr/mercframes_graphic.htm "open world" vector FPS/RPG, fully RAM-resident, in 48k & 64k editions.

* Alternate Reality: The City (Datasoft/Paradise Programming) FRPG with 90-degree turns, rendered walls/doors as scaled textures between the animated backdrop and foreground NPC sprites.

I wrote an FAQ as a kid for Mercenary for local BBS' - I think I discovered at least 3 victory conditions. :^)

There were a few.

I had Sultans Maze[1][2] and Articfox but plenty others existed too.

[1] https://en.m.wikipedia.org/wiki/Sultan's_Maze

[2] https://youtu.be/af1CfayG5Ec

[3] https://en.m.wikipedia.org/wiki/Arcticfox

I could tell something was off, but couldn't put my finger on it. Very cool