It was very weird, and it definitely lived up to the "15 Nightmares" title in that the trials were tough, and had a posterized, high-contrast visual style that made them feel dreamlike and unsettling. It was just a series of combat challenges versus oversize enemies, though, and the main rewards were the Angelus-themed weapons (which, admittedly, made the base game even easier) and vague narrative about the Old World (Legion, the Books, etc.) that was stated more clearly in the artbook. From the screens above, the high-contrast style remains but without the posterized filter.
In Gestalt, the conceit was that WoRV was a dream diary from Nier's wife, recalling him as a young man. I wonder what the plot justification will be this time, for turning Bro into the rugged old man version.