Agreed on the System Shock, and of course if we are talking about Looking Glass games you have to mention the Thief influence.

Bioshock has never been in the same category for me, because it is very focused on run and gun combat, for this reason I’ve never felt it worked as an “immersive sim”. The levels aren’t nearly as open plan either, and there isn’t anything like the focus on providing players with multiple pathways to solve the same objective. It’s still great in its own right of course.

It’s not a perfect test for defining “immersive sims” - it’s a broad term - but I do think a key attribute is being able to complete many objectives using tools other than shooting someone. Bioshock leans much more into the shooting people than any of the other games mentioned.