Someone’s beaten the mode that Doom’s developers couldn’t even beat. Ultra Nightmare combines the highest difficulty with the challenge of not being able to die once, and YouTuber Zero Master beat it in less than five hours.

Zero Master posted the proof of what he believes is the world’s first full playthrough of Doom’s Ultra Nightmare difficulty. They note that it’s not always the most entertaining playthrough to watch, “but it gets the job done.” You can watch the full run in the video below.

The YouTuber noted that you can see their helmet, which signifies they had died previously at that spot, during the encounter with the final boss. They said there were moments where they should have died in their successful run, “but sometimes you get lucky.”

Zero Master says their next challenge is to complete Doom 2’s Nightmare mode in under 23 minutes, which requires them to race through the entire game at its hardest difficulty. Their current record comes in at 23 minutes and 6 seconds.