A really nicely constructed map. Visually pleasing, great architecture, lots of detail. From the moving train, the subway style entry, turrets popping out of the floor and so on.
Gameplay wise, not really my cup of tea. It's too open ended for my taste. But I recognize it as a good map.
You should play it.
Link to Nightmare 100% walkthtough: https://youtu.be/Hnd56BRAQB0