Kosmic’s Vine Glitch Tears Versus Super Mario Bros. Apart After 40 Years

Kosmic spent another long session mapping leftover oddities in Versus Super Mario Bros., the 1986 arcade cabinet that copies most of the original NES game while changing a few rules, timers, and memory habits. Growing a vine in the wrong place after a death still queues an extra plant for the next screen. Near the top of any vine Mario loses control and auto-climbs; that state leaves a flag set so the next transition (death works best) sprouts a second vine wherever the surviving player happens to stand.

Two player mode transforms the flag into a delivery system, similar to a ticking time bomb. One player enters a land level like 5-2, snatches a hammer from a Hammer Brother who is barreling toward them, and then immediately meets their doom. Then the control switches, and boy, does the residual vine cause havoc. It decides to grow in whatever water stage the second player is in, whether it’s 2-2, 7-2, or even the dreaded Minus World. Water stages are where things get a little messy because the game starts spitting out a lot of bubbles. Now the game is attempting to initialize them in a tiny array intended solely for sprite slots 0 through 2, but the extra vine in slot 5 interferes, overwriting the low byte of the reference that informs the game where to look for enemy spawn data.

That’s when all hell breaks loose, since tile data from a previous globe is suddenly interpreted as an enemy list. So in 2-2, you’ll find bouncing Cheep-Cheeps everyplace, enormous fire bars, platforms that delete water tiles as they move, invisible items, and even Spinys that fly away at warp speed as soon as that scroll-stop object disappears. 7-2 is where you’ll discover the Lakitu that shoot fireworks, extra fire bars, and things that hide just beneath the water’s surface. Meanwhile, in the Minus world, you’ll find Koopas and fire bars that wouldn’t ordinarily exist.

One of the objects in 2-2 has an ID that essentially confuses the processor and causes it to tamper with the PPU registers. What’s strange is that it’s difficult to achieve a consistent result. Emulators and the Switch Arcade Archives port will continuously produce chaos: scores over 36 million, and parts of new geography never seen before, replete with adversaries and flagpoles never drawn by the original creators. Then there are instances when it simply reboots. Real arcade boards, on the other hand, prefer to hold leftover values in unused RAM rather than just filling it with zeros, so the same series of button presses can result in a variety of issues, such as confused graphics, a warp to 4-1, or even a full refusal to play.

100th_Coin identified the exact sequence of register crashes that resulted in the disaster, but Kosmic then mapped the same sequence onto original hardware, flashcarts, and official re-releases to see how far the corruption traveled. Then there’s Versus Super Mario Bros., which had years ago tweaked the timers to run faster and clamped down on some of those pesky warps, but the vine still finds the unused enemy initialization code and unused memory pages that its 1986 creators never imagined anyone would ever reach. Forty years later, the same small vine that previously only led to Coin Heaven is now writing new levels all over an original cabinet that was never designed to handle them.