4. Too Big in Scope for Flash

Aside from the performance issues and AS2's limitations, late in Isaac's development we soon realized that Flash simply wasn't at all made to support a game of Isaac's size. Once the .FLA file rose above 300MB, we couldn't even consistently generate an .SWF file from it without crashing.

This issue almost prevented Wrath of the Lamb from coming out at all; we were at a point in development where simply saving the .FLA would corrupt it about 25 percent of the time. Florian would have to restart his PC and save the .FLA in a new folder every time we had to export an .SWF just to test it, and 50 percent of the time it wouldn't work for no apparent reason.

It was quite a horrible experience, and if we could have seen into the future with a crystal ball, we would have simply not used Flash. (Maybe this will be a feature in Flash CS7...)

5. "Blasphemy" and Controversy

Not surprisingly, controversy made a few appearances in Isaac's release year, but not in the way you might think. During Isaac's German retail launch, the German ratings board gave Isaac a 16+ due to "blasphemy." That itself didn't cause controversy -- instead, it was the idea that said blasphemy could affect the age rating on a video game.

Blasphemy isn't something you can define for everyone (what's blasphemous for one religion isn't necessarily so for another), so how could one define something as containing blasphemy? It was a very interesting argument, and I'd be lying if I said that having the first game rated 16+ due to blasphemy didn't feel awesome, but sadly it was this controversy that I believe eventually led to Nintendo's decision not to port Isaac to the 3DS.

I remember my wife being worried about Isaac's release, worried that it might offend the wrong people and someone could end up being hurt. I can't say I didn't have some hesitation about this aspect of talking about religion in a satirical and possibly blasphemous way, but I couldn't help but avoid the simple logic that, well, most of those kind of people don't play games. And after over a year, I really believe that's true. (Thank God!)

Isaac Reborn

As of writing this postmortem, The Binding of Isaac has sold over one million units on PC and Mac in its first year on Steam, one-quarter of the people who own the main game paid for the Wrath of the Lamb expansion, and the interest seems to continue building.

A few months ago I was contacted by Tyrone Rodriguez of Nicalis (publisher of Cave Story, VVVVVV) and asked about how I felt about remaking The Binding of Isaac for consoles. I love consoles as much as the next guy, but dealing with the business end of console development wasn't something I wanted to dive back into at this point.

I told him yes, but I had a few strict guidelines to make sure an Isaac remake was perfect. I wanted the game to feature the second planned expansion that I couldn't do in the Flash version, I wanted it to feature local co-op, I wanted the graphics to be totally remade in 16-bit but still look and feel like the Flash version, and finally, I didn't want to deal with anything when it came to business. Nicalis has agreed to these terms, and development has started on The Binding of Isaac: Rebirth.

It's still too early to tell for sure what consoles the game will end up on, but both Microsoft and Sony feel like it would be a perfect fit for their digital platforms, and we have a feeling the new look might soften up a few people at Nintendo for a possible Wii U/3DS eShop release. I'm wary about how the game might control on iPad, but if they can make it work, I'm all for it.

The Binding of Isaac was a huge personal achievement. I was able to talk about something personal and meaningful in a way I felt comfortable with, and I was able to get my feet in the water with the roguelike formula and random generation.

When I started on Isaac, my goal was to make a niche cult classic, something with a tiny but die-hard fanbase. What I didn't expect was how large a "tiny" niche audience would actually be.

But what moved me the most is the amount of creativity Isaac inspired in others. Every day I read fiction blogs, watch YouTube animations, and look at others' illustrations while thinking about how honored I am to have made something that could have helped motivate so many to create.

The three months Florian and I put into creating The Binding of Isaac didn't just pay off with a financial windfall -- it also gave us an eye-opening experience that proves to me without a doubt that people truly want and respect games that are uncensored and risky, and that ask more of the player than most games these days do.

[If you enjoyed this article, please consider a physical or digital subscription to Game Developer magazine, where you'll find a wealth more exclusive content, and where this postmortem originally appeared as the cover story in the November 2012 issue. An updated, Retina-compatible version of the Game Developer iOS app is also now available.]