Tonally—and in a way that I find endearing—this is one conflicted trailer, but the mod that it's trailing is impressive to the point that Dying Light dev Techland is raving about it. Harran The Ride is a new map with a brief campaign created by Cabozzl using the Dying Light Dev Tools.
This Harran sports an abandoned theme park ride in which a handful of survivors are hiding and naturally besieged by infected. Cabozzl has single-handedly designed the map, new cutscenes and custom weapons. There's even voice work, although that's often a worrying prospect in a mod.
Harran can be downloaded from the Steam Workshop (where it's enjoying a hearty five-star rating), and while I don't want to spoil anything that its developer has intentionally blacked out, the full description is worth trawling for details on some delightful environmental threats.