As a child of the 90s, the drumbeat of the classic first person shooter Doom is permanently running through my mind at all times and I’ve played more mods for Doom than I remember. But there’s always room for another Doom mod, especially one as cool as 1337d00m, which takes the first nine levels of the game and renders them entirely in ASCII art.When the game opens, you’re presented with a slider that moves from easy to impossible. The slider controls the size of the ASCII art: At the easy end the characters are small and you can easily tell what’s going on. At the far end of the slider, the numbers and letters are huge and it's hard to tell what the hell is going on. Either way, 1337d00m is a blast to play.The mod is the brainchild of Croatian developer Dario Zubović, who created the mod over two weekends. “I had no idea what I was making,” Zubović told Motherboard via email. “[I] just wondered what would rendering 3D worlds in ASCII characters look like…I really that games like Cogmind or Dwarf Fortress continued to push limits of ASCII art long after it's a technical necessity. Developing custom ASCII shader that feels right took most of the weekend, so there was no time left to make actual game with it.”But a week later, Zubović got those ASCII shaders layered over the original Doom and created something strange and beautiful. “It's using a set of monospaced characters divided in groups by ‘density’ of the character (the more pixels it occupies when draw on the screen, the denser given character is),” he told Motherboard. “Once you know how bright certain region on the screen is, you can select appropriate character group…even without colorizing characters it's easy to recognize 3d features, our brain does most of the heavy lifting to piece the bits of information together.”This isn’t the first time Doom has merged with an optical illusion. OMDO married the magic of Doom to the wonder of Magic Eye puzzles. Which is great, if you can see Magic Eye illusions, and horrifying if you can’t.Grab 1337d00m for free from Zubović’s Itch.io here.