‘What Am I Playing, Dude?!’ Speedrunner Finds Previously Undiscovered Mario Levels After 39 Years

Quick, gather 'round everyone. New Mario levels just dropped.

You heard me. New levels. In Mario. Specifically, in Super Mario Bros: The Lost Levels, a game that first released in 1986 and which, you'd think, everyone had already discovered every single secret in.

Nope. There was still more to find. And a speedrunner named Kosmic managed to uncover over 20 previously unseen (and at times very glitchy) playable levels in the game after a lot of community help, experimentation, patience, and jumping off springs.

Kosmic has recorded his full journey in a 40-minute video here, and I highly recommend watching it because he does some crazy stuff and has a detailed explanation of how and why this works the way it does. But very, very basically, in the original Super Mario Bros. and its sequel, The Lost Levels, the game determines what level and world to send you to at the end of each level based on what object you "use" to clear the level. Grabbing a flagpole increases the "Area" number by 1 (the "2" in "1-2") while grabbing the axe on a castle bridge increases the "World" number (sending you to "2-1" after beating "1-4", for instance).

Then there's Warp Pipes. For years, the Mario community has known about the infamous "Minus World" glitch - an infinitely-looping water level accessed by entering the Warp Zone in 1-2 in such a way that the zone doesn't fully load, and the pipes aren't set up yet to send you to the correct world and area. In the original Super Mario Bros., doing this and then entering the far left or right pipes sends players to a level designated "World -1", or Minus World. In The Lost Levels, this glitch was removed, with the pipes instead sending players to whatever destination is currently loaded into its memory. But if you enter the pipe while moving, the Warp Zone can load after you've entered, and you can trick the game to send you to the very beginning of the Area that the pipe wants to send you to.

That's all pretty complicated, and honestly it's making my head spin too. Again, Kosmic's explanation is the best one, but the even shorter version is that using a combination of flags, axes, and pipes, you can manipulate the game into sending you into increasingly unhinged areas. You can force the game to load wacky stuff like World 2-5, 2-9, and so forth. And in The Lost Levels, quite specifically the Super Mario All-Stars edition, this weirdness is compounded by the fact that the game has save states accessible from the menu that will save your access to these weird worlds, but will load them in differently if you're accessing them from the menu instead of from the previous world.

Kosmic was able to combine all of this to start loading world after world beyond The Lost Levels' lettered bonus levels. First, from B-4, he made it to B-5, then B-6, 7, and 8. With some difficulty, he reached B-A, B-B, B-C, and B-D. Up to this point all these levels were largely just repeated versions of other levels, albeit with some occasional weirdness. But after B-D, it was unclear what was going to load.

The answer was B-E. At first, it just seemed sort of silly. Then, Mario briefly went to jail:

The only way out was to save and quit. Kosmic escaped, headed to B-F, which started a series of repeat normal levels. From here, he went all the way to B-L, after which point a spring and a giant pit stopped him from playing further. But he could still load all these levels from the menu for different variations, and B-H resulted in this:

Things only got weirder from there:

In total, Kosmic found over 20 "new levels", which ranged from nearly identical to existing levels, to total messes like what you see above. Eventually, playing them just crashed Kosmic's game, and they're probably not that fun from a platforming perspective, but they were cool to see.

So why did it take 39 years to find these levels? Kosmic has theories:

"Fewer people played Lost Levels compared to the first game. This trick is deep into the game, like in bonus worlds, not even in the main worlds. To see the full extent of the glitch, it only works on the All-Stars version, and it gets a bit technical...but the main reason I'd say is it's actually really hard."

Kosmic demonstrates this in his videos. The most difficult part about it involves entering a pipe when the Warp Zone isn't fully loaded in, which requires being very precise with your movement as well as where the camera currently is. Some levels are easier to manipulate than others, but for this glitch to work there's one particularly tricky Warp Zone that Kosmic had to pull some very specific tricks to master.

Congrats to Kosmic and the entire Super Mario Bros. community, who now have a bag full of weird new levels to mess around with and the certainty that it's never too late to discover something new about a classic video game.

Rebekah Valentine is a senior reporter for IGN. You can find her posting on BlueSky @duckvalentine.bsky.social. Got a story tip? Send it to rvalentine@ign.com.