The game is described as a puzzle-based, deckbuilding roguelike and follows Bumbo, a familiar introduced in 2015's The Binding of Isaac: Afterbirth expansion.ĬBR caught up with McMillen to talk about The Legend of Bum-bo, how his experience as an indie developer has changed over the years and Mew-Genics, his long delayed project with frequent collaborator Tyler Glaiel McMillen's newest project is The Legend of Bum-bo, which is a prequel to The Binding of Isaac. Between 2010's Super Meat Boy and 2011's The Binding of Isaac, Edmund McMillen is one of the biggest indie game developers working today, with his games having earned a lot of praise over the years.