Merrifield co-founded Club Penguin, a massively multiplayer online role-playing game for kids, in 2005 and sold it to Disney in 2007. Club Penguin boasts nearly 200 million accounts.
"Over the past year, I've invested in a new educational startup called FreshGrade that focuses on creating mobile cloud-based assessment software for teachers and students and it has reached a place where more of my time is needed," he wrote in a letter to employees. "We started Club Penguin in order to enhance our children's online experience and now I hope to do the same with their educational experience."
The interactive division at Disney, which encompasses Walt Disney Interactive, has struggled recently. In filings from August, the company reported that the division lost $42 million in the quarter. According comScore numbers cited by the the L.A. Times, Club Penguin's monthly traffic has decreased to 3.3 million from a high of 8.5 million in December 2009.
Disney Interactive acquired Black Rock Studio in 2009, but closed the studio in 2011 after the release of Split/Second. Disney Interactive's Propaganda Games, developers of Turok, Turok 2 and the cancelled action RPG Pirates of the Caribbean: Armada of the Damned, was closed in 2011.
Be sure to check out Polygon's recent interview with Warren Spector, founder of Disney Interactive-owned Junction Point, the developer behind the Epic Mickey series, were he spoke about working with Disney Interactive and his aspirations.