The progression through the levels was also challenging with the key/door/secret placements as well as with ammo being more sparse and having to change up weapons a lot more often to conserve ammo. They felt more like real places than a lot of the original Doom 2 levels with big sprawling open areas, multiple branching corridors, views into multiple different rooms, lots of good secrets, and tons of enemies. The levels were much more complicated than the original Doom 2 levels, which was likely due to them being created so many years later.
I ended up liking this episode a lot more than I thought I would have.