If you're looking for Kurt Kesler's vanilla levels, they're all collected in KMEGA1. His Boom maps weren't, but they're neatly organized as the KBOOM series. There are also a few limit-removing maps as the short-lived KHILLS series, an attempt at source port agnostic levels from when Kesler got badgered into briefly abandoning Boom. They must have wailed during his final run of PWADs, since the KZDOOM series is even more selective than Boom insofar as what maps made for it will run in. KZDOOM5 aka "The Evil Place" is something of a return to form after KZDOOM4. The previous map was a brick and wood castle theme that Kesler rarely played with as he found it difficult to get in to. This one is a big ass industrial complex set in a giant lake of slag.
KZDOOM5 is loaded with hitscanners. Zombies show up in full force and are often on different tiers of play that harass you to no end. You wouldn't get this from the opening action since you're stuck between a rock and a hard place with revenants inside the building and cacodemons pressuring you on the out, but the former humans are lurking just about everywhere. The blue key complex is a particularly dangerous moment since they're crammed in everywhere on the bottom and top, plus Kesler has a questionable forest to walk through on your way to the exit that has shotgun guys spread out. Of course, Kurt isn't dumb and has liberally seeded health throughout the map for you to restock when you're wanting.
The industrial building looks pretty cool with all its 3D grating and moving parts but the map is almost uniformly bright, robbing the base interiors of some much needed contrast, not that anyone minds being able to see when there are shotguns and chainguns just dying to be pointed at you. The forested canyon has a pretty neat look except for the fact that Kesler's texture for the walls looks hopeless when tiled on a large scale, a problem ubiquitous in Doom. The northeastern area is more oldschool Kesler but on a claustrophobic scale with all those computer banks and pillars to hide zombies behind. The blue key ambush is a nice fight; I was finding straggler imps for ages.
I don't like the finale; you have to kill the Icon's guardian Cyberdemon from across a fiery fissure to activate it with your only sensible choices being the single shotgun or rocket launcher. It just takes a long time which isn't very interesting and afterward you've got a token Icon encounter to handle, exacerbated by the jerky movements of your shooter platform (though you can always mouselook your troubles away). Still, I like the map pretty well, and it's about par for Kesler if not exactly as distinguished as his other KZDOOM offerings. Play it; you might enjoy it!