SimCity creative director Ocean Quigley and a pair of other lead Maxis developers have left Electronic Arts to establish a new studio--Jellygrade--Quigley announced today on Twitter.

"I'm done with EA. This is a small, independent studio," Quigley said.

Joining Quigley at Jellygrade are Andrew Willmott and Dan Moskowitz, who worked on SimCity as simulation architect and lead gameplay engineer, respectively. The trio have been with EA for years, serving in lead roles on SimCity 4, Spore, and The Sims 2.

"We love making simulations," Quigley said.

Jellygrade's new game is a simulation title for tablets that is focused on the dawn of life on Earth, and will center on lava, water, rock, and the emergence of the first primordial creatures, Quigley said.

A few pieces of concept art are available on the Jellygrade Tumblr. Quigley said he hopes to share more details about the project soon.

SimCity's launch in March was marred by server woes, though this trouble has not kept the game from selling 1.6 million copies since launch. The game is due out for the Mac in August.