There's one core campaign to Back 4 Blood, which is PvE and absolutely designed for co-op. The concept of multiple runs, then, is pretty important, and you can see how the game, odd as it may be up close, is very much built out from that point. Back 4 Blood is also a game you play through more than once, but this time it is built that way. Left 4 Dead was not really a game you played through just once, but aside from the general morishness of the co-op it wasn't necessarily built that way.
As you may well know by now, Back 4 Blood is a close spiritual successor to Left 4 Dead, being developed by original Left 4 Dead studio Turtle Rock - once known as Valve South, during the Left 4 Dead years, before it was re-founded in 2011 again by some key names like Michael Booth, Phil Robb and Chris Ashton - and the history here is important. Much of this comes down to its system of runs. Scrabbling around in the game's oddly enticing dark for long enough has allowed me to admit I was very much wrong.
