Edmund McMillen and Tyler Glaiel had barely had time to launch Mewgenics before the game sold so well that it made back its development budget. A day later, we learned the game had sold 500,000 units in 36 hours, and it didn't stop there.
Very positive reviews and word of mouth has lead to Glaiel now revealing that Mewgenics has sold more than 1 million (or mewllion to be precise) copies this first week since launch.
He also brings some very minor disappointing news, as the first patch has been delayed until the end of this week because he has caught a cold. Gotta love these kinds of details about a very small project.