It's a large departure from the formula of DOOM1 & 2, and I think it achieves most of it's goal of giving more of a horror experience rather than action, but it struggles since it can't really find a perfect balance of the two. The shadows and lighting are great even today, if a bit sharper than you would expect, and I feel like part of the horror is lost with the mounted flashlight. The abysmal shotgun seems like a result of the much smaller enemy counts compared to DOOM 1 & 2 and Quake 1 & 2, which is mostly negated by the assault rifle you get early on. The game definitely can catch you off guard if you let it, and the restricted lighting can make you nervous since your line of sight is usually very obscured. The level design isn't very memorable and can feel repetitive, but it does a great job giving the impression of a futuristic space station. Combat feels very weak, and can be frustrating due to the damage causing the screen to shake, and the weapons are a mixed bag, the chaingun and rocket launcher definitely feel as powerful as they should be, but the plasma rifle and BFG feel lacking. The whole game feels like a mixed bag, which I enjoyed though the repetitive level design made the game feel like it was dragging on.

I played both expansions, thought both of them were alright, more combat focused, not that long, if you didn't like the main campaign that much I wouldn't bother.