It’s been almost 30 years since Super Mario Bros. 3 released for the NES, but we’re still discovering cool new secrets in 2017. In this case: never-before-seen levels that happen to be hiding within SMB3.
Shesez runs Boundary Break, a YouTube show that’s kind of exactly what it sounds like. Using special tools and mods, Shesez peeks out and beyond the frames of what a game wants you to see. Turns out, many game worlds are held together or sprawl in surprising ways—and you can sometimes interact with that stuff.
This time around Shesez tackled Super Mario Bros. 3, only to find that on World 2, certain icons act as level tiles—meaning that if you press on them, they’ll teleport you somewhere else. Sometimes, these tiles just make the game crash, or they’ll throw you into a Toad House, but sometimes, they’ll load a glitchy level. You can see this in action around 2:15 in the video, which you can watch here.
These levels have all sorts of objects you can interact with, including secret doors that can send you back into the title screen. Pretty cool, huh?
“The hair stood on the back of my neck when I found the first [glitch level],” Shesez told Kotaku. An average player could theoretically duplicate his results by using a Game Genie code on the actual NES. “This happens consistently, so you could essentially label these the secret glitch levels of Super Mario Bros. 3,” Shesez says in the video.
The whole thing is worth a watch as it’s filled with neat little tidbits about how a classic game works, so make sure to check it out.