According to game designer Edmund McMillen, The Binding of Isaac has sold more than 700,000 copies to date. This was made possible with help from the "Wrath of the Lamb" expansion, which sold 1/5th of the overall sales in "less than three weeks."
"Who would have thought a game about an abused child fighting off his mother with his tears could ever sell 700k copies in less than a year? Not me, that's for f**king sure," said McMillen. Since the launch of the add-on was "a bit rocky," the team has put out a free update that includes fixes and new content ranging from achievements to music to yet another ending.
"This is also a big thank you to the fans who have honestly carried this game to stardom, we are eternally grateful for your support, creativity and devotion. 700k is a big number... maybe it's time to bring this thing to console. ;)"