It is a decently built campaign, especially considering its age, but the quality still drops from time to time. The maps are littered with panic events with rare health and ammunition, and tons of gas and propane cans with no real way to use them when you run out of ammo and brandish nothing but a melee weapon. Some crescendos come out of nowhere and never stop. The game instructor doesn't show where to run in the finale, and there also is an invisible wall. The campaign's difficulty is so highly artifically increased, that I actually swore audibly while soloing on Normal at least at two points. You did it on Death's Door Expert? Keep your trophies, then.