Imagine: You're playing Link to the Past, the seminal Super Nintendo action-adventure game, and you walk into a fortune-teller's house, where you'd expect to find a soothsayer taking rupees in exchange for hints.
Instead, the screen goes black for a few seconds. Suddenly you're on Zebes, fighting aliens as a suited bounty hunter. Whoops, you've just walked into Super Metroid.
What might have once seemed like outlandish fanfiction is now a very real ROM hack that you can download and play, combining Zelda and Metroid into a single game. It's not quite that simple, though. This crossover hack is an extension of the Link to the Past Randomizer, which swaps the locations of every item in Hyrule, spicing up the game by forcing you to play everything out of order.
This, the spicier version, swaps the locations of every item in both Link to the Past and Super Metroid. You might find Samus's Morph Ball in Zelda's Misery Mire, while the Power Gloves could be stuck in a tunnel deep inside of Lower Norfair. In order to make progress, you'll need to know what all of those words mean, which means you'll need fairly comprehensive knowledge of both games.
You can get the ROM hack, which launched today and requires you to upload your own ROMs of Zelda and Metroid, right here.
This 'Link to the Past + Super Metroid Crossover Randomizer' was created by Thomas "Total" Backmark, 35, a software developer in Sweden, who told me in a recent interview that it all started as a joke. The speedrunning communities for both games share a lot of members, and at one point during a Discord chat, someone suggested that they make a crossover game, where you'd find Link to the Past items in Super Metroid and vice versa.
"Now we're talking," Backmark wrote, according to a Discord log he passed along. "Just romhack the two games together, and when you go through certain doors you switch games."
The idea stuck, and as he was playing around with ROM files for each game, Backmark discovered something fortuitous. The Super Nintendo's memory bank, he explained to me recently, is split up into 256 segments. Link to the Past and Super Metroid were both coded to occupy different groups of these segments, perhaps coincidentally.
If they had overlapped, they wouldn't be able to share a ROM file, but because they each took up different parts of the SNES memory, they could work side by side.
In other words, it'd be possible to mash Link to the Past and Super Metroid together as a single Super Nintendo game.
"It turns out after working a bit on that it was possible, and I could create a simple proof-of-concept with both games in one ROM that allowed travel between them," Backmark told me via Discord. "But even with both games working it wasn't that easy to actually switch between games and keep enough state so that progress was saved and it didn't crash."
After a great deal of work and some creative use of save states, Backmark found a way to pull it off, and over the past few weeks, he's recruited other members of the ROM hacking and speedrunning communities to play through his crossover.
"It's been a lot of fun," said Andy Laso, a popular Link to the Past speedrunner who recently started streaming the Metroid-LTTP crossover. "It's definitely very draining. I can whip out Link to the Past Randomizers in my sleep, but Super Metroid-Link to the Past crossovers I have to use my brain a lot more."
Laso, who started speedrunning Link to the Past in 2012, told me he's since been able to turn his streams into his main source of income. He streams regularly on Twitch and has done some incredible live runs at Games Done Quick, often beating Link to the Past in ridiculous ways - without a sword, for example.
For him and other members of the Link to the Past community, the Super Metroid crossover is another way to spice up a game that Laso says he's played for thousands and thousands of hours.
To beat this crossover, Laso explained, you need to finish both Super Metroid and Link to the Past, zipping back and forth between the two games as you get specific items that will help you unlock specific paths.
The crossover points are predetermined, but all of the items are random, so playing through the ROM optimally means knowing exactly which paths to follow based on which items you get.
"Generally I'll have a path in my head of what I'm going to do, depending on my current item set or whatever," Laso said during a recent phone interview. "If I find another item, I'll have to change my route on the fly ... I'm always planning ahead. Super Metroid just adds a lot more things I have to plan. Walking through either Super Metroid or Link to the Past, I'm like, 'Oh I found the Varia suit, now all this stuff is open to me. Oh, I found the flute.'"
The Metroid-LTTP crossover uses a modified version of the Link to the Past Randomizer's algorithm, which is designed to prevent soft-locks. In other words, you're not likely to get stuck because of the order in which items have been placed. But you do need to know a bunch of speedrunning glitches and tricks - like wall jumps and bomb jumping - in order to play through the Super Metroid portion of the ROM.
If you don't know both games by heart, you're probably going to have a bad time.
"These old SNES games are something that I grew up with when they were new," said Backmark. "So it's fun coming back to them and hacking around and doing awesome projects with them."