The Binding of Isaac: Four Souls isn’t just some licensed card game spin-off, it’s not a trend-following Hearthstone clone, and it has nothing to do with The Legend of Zelda: Four Swords, despite the awesome logo.
Instead, Four Souls is a Binding of Isaac physical card game lovingly made by Edmund McMillen, the creator of Isaac and Super Meat Boy, because he wanted to make a Binding of Isaac card game. Newly launched on Kickstarter, it’s seeking $50k to finish up that production.
Source: IGN.com The Binding of Isaac: Four Souls Announced