More than 20% of those that play casual games like Peggle and Bejeweled have some sort of "physical, mental or developmental disability," according to an Information Solutions Group survey commissioned by casual game developer PopCap Games.

The survey encompassed a total of 13,296 casual gamers--a market that, mostly driven by web-based applications, is estimated to have between 300 and 400 million players worldwide. The latest U.S. Census states 15.1% of the American population is disabled.

Depression, ADD / ADHA and Rheumatoid Arthritis / Osteoarthritis respectively ranked as the most common types of mental, developmental and physical conditions. Only 26% of disabled casual gamers were said to play traditional video games.

The study notes that those with disabilities typically play casual games more frequently and longer than the non-disabled, and find the benefits to include stress... Read more

Rockstar vice president and Grand Theft Auto IV co-writer Dan Houser said that though the gaming industry has shifted progressively towards casual experiences and a broader market, his company will stick to large-scale productions.

"Fuck all this stuff about casual gaming," Houser told New York Magazine. "I think people still want games that are groundbreaking. The Wii is doing something totally different, which is fantastic."

"We're hopefully going to prove that there's also a very big audience for people who want entertainment in another form, who think of games as being a narrative device that can challenge movies," he added.

Houser noted that future Rockstar productions will continue to focus on themes similar to those established in previous titles.

"They're gonna be about themes that interest us whatever the medium, instead of the weird, special video game-only themes that too many people make—orcs and elves, or monsters, or space," he said. "We felt you could make a good game and have it be about something we could actually relate to. Or aspire to."