Whoops. "Gameplay" was a Freudian slip but if I recall this was exactly how it was marketed. At the time I was super into Brute Hughes (kmfdm by proxy.) what sucks is Marathon's engine was pretty cool compared to Doom's.
I had seen a preview of this in PC Gamer in the 90's, and thought it looked great. I finally found a used copy for sale in the early 2000's. I actually played it quite a bit to try and see all of these cut scenes.
The game itself is an ugly, boring and repetitive mess. It was one of those games that really seemed like it was designed with and for the macintosh.