Gave the solo Z version a shot. It seemed a lot darker than the video, possibly too dark! Didn't last long, went out the back door where you start, went up and round to what seemed like the map edge and got stuck towards the waterfall with a never-ending stream of zombies till I ran out of bullets, mostly because it was so dark I couldn't work out where I could actually go. I gave it a like out of solidarity ;-)
You have to destroy the canisters on the zombie respawners (I think there are 3 of them) you can see there location easier by climbing onto the top of a caravan they have orange beams going up into the air.
Destroy all the canisters and they shut down stopping zombies from respawning, it's a tough map I closed down 2 of them and got wasted trying to do the 3rd, It's doable I should have ran and then returned instead stayed and took on too many enemies.
At the start let the vultures fight it out with the zombies and go straight for one of the respawn stations.