The Binding of Isaac: Rebirth was always meant to be a Nintendo game, but the restrictive rules from the 100-year-old Japanese platform holder torpedoed that idea.
When the game was announced for Steam, PlayStation 4 and the Vita instead, most thought that original concept, putting a Zelda-inspired game about the unfortunate son of a crazy zealot on a Nintendo platform, was a complete impossibility.
But not game makers Tyrone Rodriguez and Edmund McMillen and not, it turns out, a trio of stalwart fans of the game inside Nintendo.
Earlier this week, developer Nicalis announced that The Binding of Isaac: Rebirth was headed to the Xbox One and two Nintendo platforms: the Wii U and New Nintendo 3DS. The game is expected to hit before this year's E3 in June and will cost about $14.99.
But how did the game makers suddenly win over Nintendo?
"The short simple answer is we were very persistent and had a few big fans at Nintendo that helped with our pushing," McMillen told Polygon.
Rebirth is a remake of the original The Binding of Isaac, which was designed by McMillen and Florian Himsl and released in 2011 for Linux, Mac and Windows PC.
In the game, players take control of a naked, crying child named Isaac. The child flees to the monster-filled basement of his home after his mother receives a message from God demanding she take Isaac's life to prove her faith. The game plays as a top-down, procedurally generated 2D dungeon crawler. Players must find and defeat a boss on each floor of the basement to proceed to the next level. There are also special items, money, keys and shopkeepers. The mechanics and presentation of the game were inspired by The Legend of Zelda. Useable items in the game include a sanitary napkin, poop and his mom's bra.
The Binding of Isaac: Rebirth was a 2014 remake released on the PlayStation 4, Vita, Mac, Linux and Windows.
"The initial idea that Ed and I had for the game was to do it on 3DS," Rodriguez said.
But Nintendo quashed the game's release on 3DS.
"Questionable religious content."
At the time, McMillen tweeted that Nintendo decided not to allow the game on 3DS because of its "questionable religious content."
But Rodriguez said in an interview with Polygon today that that wasn't completely the case.
"It wasn't entirely religious related," he said. "I can't speak for Nintendo, but the game was a little controversial at the time. Since then things have changed in terms of what can and can't be on their platform.
"My understanding is that they now rely on the ESRB for guidance. Anything that is rated from E (for Everyone) to M (for Mature) is OK, but AO (Adults Only) can't be on their platform. I think this and a few other games were the impetus for that change."
A big part of convincing Nintendo to change its opinion on the game was Nintendo itself, or rather three key employees at the company, Rodriguez said.
The trio, vice president of licensing Steve Singer; Mark Griffin, a senior manager in licensing game development at Nintendo; and the company's head of indie development Dan Adelman, all continued to push for the game's release well after Nintendo's official, public denial.
Adelman eventually left Nintendo after calling the company out on Twitter over its region-locking practices and a need to be more flexible in terms of what content should be allowed on the company's systems.
"They all pushed hard for the game to happen," Rodriguez said. "I've been pushing hard for this to happen too, with their help. I'm a huge Nintendo fan and it was a personal goal, not a stubborn goal, but a goal that I approached very amicably.
"I wanted them to know how important they are to me and how important it was to get the game on the platform."
Back when McMillen and Rodriguez were first talking about Rebirth they viewed it as a Nintendo exclusive, Rodriguez said. Not because of any existing deal, but because it felt like a good match for a game so inspired in its design by Zelda.
It wasn't until they had been working on the game for a bit that they realized it wasn't going to be going to Nintendo.
"They never really said no. Maybe this is a nuance, but it was never an official no. They just never said yes," Rodriguez said. "It was a very delicate thing because we have a long-standing relationship with them and pushing too much wasn't advisable."
So the team decided to move forward, shifting the game to Steam, PlayStation 4 and Vita.
"But the conversations with Nintendo never ended," Rodriguez said. "It was very casual. Every two months I'd check in with Dan and check in with Steve.
"Then last year we had a secret meeting and were approved."
The secret approval, while not entirely unexpected, came out of one in a long series of meetings near the end of last summer. But now that they were given the greenlight to bring the game to the 3DS they had another, potentially bigger problem, one caused the limited tech of the 3DS.
"When we originally had the idea to bring the game to the 3DS we had a feature set that was an 8 ounce cup of water," Rodriguez said. "And then when we shifted to the PlayStation we upgraded to a 16 ounce cup of water.
"Then when Nintendo came back and said yes we were like, 'Oh crap, how do we get this back into that 8 ounce cup?'"
After some work the team managed to get the game running on the 3DS, but not to the quality that anyone would have liked.
"People would have said it was terrible," Rodriguez said. "So we decided to look at the New 3DS."
Initially, they couldn't even get their hands on prototype developer kits for the new console, but thanks to some help from their friends at Nintendo, they ended up being the first studio to get the kits in the U.S.
"We found that the New 3DS was a lot more powerful," he said. "There was additional performance, more memory, making it feasible to run at 60 frames per second."
A lot of that horsepower comes from the random generation that powers the game and makes it such a delight to play over and over again. Rodriguez said they would have also had to redo the art to make it work on the original system.
If the New 3DS hadn't come along, Rodriguez said they would have still figured out a way to make the game work. But, he said, instead of taking six to eight months to build, it would have likely been longer than a year and it wouldn't have been the same game.
Will it ever come to the original 3DS?
"Officially, I'm going to tell the internet no," he said.
The New 3DS version of the game will be identical to the one you can currently pick up on Steam or the PlayStation Network. The only real difference is that the 3DS version has a map on the bottom screen and as much user-interface as they could fit.
"Everything else is the same," Rodriguez said. "Every foul thing is still in there."
While the game won't ship with any of the new content, like the After Birth DLC, Rodriguez said it's possible they may sell that content down the line for the 3DS as DLC.
"If Nintendo's infrastructure for DLC is better than it was during the Wii era, I think it's possible," he said. "We tried to do DLC for Cave Story and the certification process was such a terrible disaster that we canned it and gave it away.
"It seems as if over the last five years Nintendo has tried to improve that infrastructure."
Rodriguez and McMillen are just happy they can finally bring the game to the 3DS, where they've always thought it belonged.
"It's great to finally release something on Nintendo consoles," McMillen said in an email to Polygon. "I never expected my first game would be Isaac though :)"