“Things running Doom that weren’t meant to run Doom” is a category that’s been with us for years now. Pianos, printers, the screen that shows your order in a restaurant, a motherboard BIOS, gut bacteria, Doom itself: The list goes on and on. And now that list is just a little bit bigger, as UEFN developer Jackson Clayton revealed that he’s brought the classic id Software shooter to Fortnite.

A video of the work shared by Clayton on Twitter (via Kotaku) starts off innocently enough. That’s E1M1, alright, complete with weird angles, low-res textures, and a distinctly flat space marine waiting for someone to lead him into battle against the minions of Hell. It takes a turn a few seconds in, though, when he jumps out a nearby window (which you absolutely cannot jump out of in Doom, and trust me, I’ve tried many, many times) and begins slapping together shoddy wooden ramps and platforms.

This is not Doom at all! And it’s not, really: Clayton told Kotaku that UEFN’s programming language is “too high-level” to actually get Doom running in Fortnite, so instead he had to fake it: He used Ultimate Doom Builder to export E1M1 as a 3D model, which he then imported into Fortnite’s editor. After that, he said most of the effort went into making it look “unlit and unfiltered,” and to give the space marine its familiar “choppy spinning effect.”

“It also helps a bunch that I have released a number of Doom-inspired games on Steam in the past before moving over to UEFN, so I have experience with replicating its visual and gameplay style,” Clayton told the site. 

Clayton said he undertook the Doom-in-Fortnite project even though he knew he’d be unable to release it publicly so he could learn more about UEFN, and also as a way to “trick my friends,” which honestly is a pretty good reason for doing just about anything. They convinced him to put the video on Twitter, and the rest, as they say, is history.