It's not BAD by any stretch of the imagination, but it can get repetitive, especially as the campaign runs you through the same location several times but on different non-converging paths. However, the level design is very much typical L4D, which is to say downtown city buildings, tunnels and interiors. The map has been retrofitted to include some L4D2 elements, such as gassing up an engine (of a tank, no less) and shutting down a blaring alarm, which brings the experience up to a decent level.
They must work together to brave the infested streets, many of its buildings and even part of its underground in search of rescue.
It puts Coach, Rochelle, Ellis and Nick in the heart of the eponymous dead city, having taken shelter in a cellar. Dark City II is a L4D2 remake of the L4D campaign Dark City.