The Binding of Isaac was Supposed to Fail

By Kotaku on at

By Alex Calvin

When he released The Binding of Isaac, Edmund McMillen thought that no-one would like it – but that was okay. The title – which has now sold over 5 million units – was created as a reaction to the mainstream success of his previous game, Super Meat Boy, which propelled the indie hero into the spotlight.

In McMillen’s own words, following that hit, he wanted to make a ‘fuck you’ project.

“A lot of people don't realise that I made like 30 games before Super Meat Boy,” McMillen says. “All my industry peers were becoming hugely successful. It was like: ‘If I want a future, I have to do this and do it right and do it to the best of my abilities'. It was time to get serious and do something before the bubble popped. That was Super Meat Boy."

“Afterwards I wanted to go back and prove that I don't need to chase the dollar again, that I don't need to make another blockbuster indie game – which is funny at this point. I wanted to make something that was the opposite of that. I wanted to make a really risky, weird and abrasive game that would push people away from it.”

“I wanted to do a 'fuck you' project, just to say I'm still independent.”


It’s easy to see why McMillen thought people would not gravitate towards The Binding of Isaac; the title is part of the niche roguelike genre of randomly generated games. Not only that; it features strange, often disgusting, environments and items, and has dark family and religious themes. Dying also means losing everything and going back to the start.

“I went in thinking I will make a randomly-generated game, I’d keep it nice and simple and have a lot of pretty familiar mechanics,” he explains. “I was riffing off The Legend of Zelda, very obviously. I thought I can randomise Legend of Zelda dungeons and make it a whole new, totally different game. From there, I thought about what kind of themes I wanted to bring into it. I asked 'what would Miyamoto do?’; he pulled from his childhood experiences when making Zelda, so I did the same. I guess mine were darker and weirder."

“I really wanted to do something totally off-the-wall, totally not user-friendly. I wanted to make something that I would really like, but I didn't think most people would like.”

Though it was a conscious decision to make The Binding of Isaac personal, in hindsight McMillen says he put much more of himself in the game than he originally thought.


“I didn't realise how much of myself I put into the game until the birth of my daughter,” he says. “One thing I didn't realise about having kids is that when you have a child, you relive your life and think what your parents were doing when you were aged one and what the situation was then. You live through your childhood again. You start realising some crazy shit."

“It feels a lot more real and personal at this point. Not in a literal way – I didn't have a crazy mother that was super religious – but I definitely felt very much like a black sheep and total alien when it came to my family.”

What was meant to be a two-week project soon turned into a three-month project, and before long it was ready to launch. While his wife was worried that the title might attract negative attention from religious groups due to Isaac’s themes, prior to release McMillen himself was convinced that the game would do nothing. He was worried that it wouldn’t even make it to Steam.

“I didn't think it was going to do well,” he recalls. “I was fine with that. It was a three-month project; I could take the risk of failure and it not be that bad financially. I had a cushion behind me from Super Meat Boy and I thought I'd do something like I used to.”


“I didn't even think it was going to get on Steam. I shipped out a prototype to a few respected developers, one of which was Jonathan Blow. He said I should put it on Steam. I didn't think they would put a garbage Flash game on Steam, but figured I might as well try."

“This was around the time Greenlight launched so I was scared shitless. If Steam said okay, it would be awesome, but I thought it probably won't so I did this whole big sales pitch trying my best to sell it. Steam said it would go with it and see what happens. I was like: 'Really? This is going to be the thing that closes the door with Steam – this little shitty Flash game that nobody likes and they're going to stop responding to my emails' – but that didn't happen."

“It's surprising to me that it is where it is today. I still don’t think people even see it for what it is. It's become a video game so you just take it at face value.”

For a while, McMillen’s prediction was right. The game didn’t have much mass appeal following its September 2011 release. But the following summer, it just exploded.


“Suddenly all the kids that had heard about it started playing and streaming it,” McMillen says.

“That was the big streaming boom; there were so many pretty popular Let's Players streaming it. It's the perfect game to riff over while you are playing. You can just say whatever. It's easy pickings when it comes to having commentary over something as it has so many bizarre elements and weird interaction."

“That summer it just exploded, it was so unexpected. The project I had only worked on for a little bit of time had at that point exceeded Super Meat Boy in terms of sales.”

But beyond streamers being able to easily talk over it, McMillen say there are a number of reasons why The Binding of Isaac became popular.

“There are a lot of elements of the game that I think people really dig,” McMillen explains.

"I’m an obsessive collector of things, and Isaac scratches that itch where you're always seeing and collecting new stuff and seeing how it all works together. On the surface, that's the main appeal of levelling up this random character and seeing how things stack together and never knowing what's next. You always have that carrot in front of you to keep on going because you don't know what's going to happen."


“Another element is the ‘fuck-you’ factor of the game; how it can just screw you over. A lot of people can be up in arms about that aspect of the game but deep down it's quite appealing, especially to watch. It’s a living thing with all these moving parts."

"One of the most appealing things about the game that nobody talks about and nobody completely realises is that the game is always asking you to do little maths problems. You're always rolling probabilities in your head; you're doing it subconsciously. People are min-maxing every little thing to figure out the best way to do something so they can get more items. That's hugely appealing and nobody ever realises that's happening.”

Now McMillen is looking to his next project. Though he has announced development on other un-released titles, including The Legend of Bum-bo and Øuroboros, this game is a platformer about stress, anxiety and the end of the world. The currently-unnamed project is built in the engine that McMillen and Tyler Glaiel used for Øuroboros and is now five months into development: “It will look like a lot of other games that I have done. That's the one response that I've had from different people testing it. It feels like every game I have made all mashed into one game. I can see that.”

Yet McMillen has found it hard to leave Isaac behind, and the game's popularity has kept him imvolved. Following the sales boom – and the Wrath of Lamb expansion in May 2012 – McMillen was approached by publisher Nicalis to release the game on console. The team took the title out of Flash and launched The Binding of Isaac: Rebirth in November 2014.

Since then, McMillen has added to the game with the Afterbirth and Afterbirth+ expansions, in October 2015 and January 2017 respectively. Following the latter’s release – and the inclusion of mod tools – ‘Booster Packs’ of the best community mods started being released on a monthly basis from March 2017, always including a little something from McMillen himself.

So why does he keep returning?


“The weird answer is that my wife is a really big fan of the game,” he laughs. “It was the only game that I have made that she has been sucked into. But it's by far the most personal and most 'me' project I have ever made. It's very raw and embodies my whole life and career. There are so many elements that are pulled from who I am. It's hard for me to put down. It was very enjoyable to work on."

“It's nice to be able to close the book. We’re working on a Booster Pack right now and I'm not happy unless at least one of those items is made by me. I need my hand in that; I need to continue to do this and try and improve it. I really want to make it as good as possible so when the Booster Packs stop, it becomes this perfect little time capsule that is untouched.”