The game started its development around 2017 when
Javon Frazier of Studio71 US approached McMillen; Studio71 was in the process of making the
Cyanide & Happiness card game,
Joking Hazard, and had asked McMillen if he was interested in a board game variant of
The Binding of Isaac. At that point, McMillen was still focused on developing
The End Is Nigh and
The Legend of Bum-bo, and declined the offer. About a year later, McMillen had gotten the flu, and during his off-time, came up with a card game variant for
The Binding of Isaac. After prototyping enough of the game for about two months, he recontacted Studio71 to work out the fuller details for the game. Studio71 had suggested the
Kickstarter route for gaining funding for the game, as they had used that successfully for
Joking Hazard. McMillen was wary, knowing that digital-based Kickstarters could fail, but agreed to using it as long as they had a nearly-ready product to be sold at the start of the Kickstarter, and that he could expand on the game by adding new cards when extended Kickstarter goal tiers were met. The Kickstarter, revealing that this was a card game, was launched two days later; within only a few hours of the launch of the campaign, the project was successfully funded, receiving its goal of $50,000 within the first 1.5 hours. The Kickstarter ended with 38,335 backers pledging a total of $2,650,875. ==Release==