• by Mark Walsh  @markfwal, April 15, 2010

Mobile gaming is more than ever a tale of two devices: feature phones and smartphones. The U.S. population playing games on regular mobile phones fell by 35% last year to 29.5 million, while the number of smartphone gamers shot up 60% to 21.4 million, according to a new comScore study. The mobile gaming audience overall has dropped 13% to 51 million.

The dramatic shift in mobile gaming toward smartphones underscores both the proliferation of high-end devices and how critical a platform they have become for both casual and serious gamers. The iPhone alone last year accounted for 5% of U.S. video game sales, or about $500 million, according to a recent study from mobile analytics firm Flurry.

"As the market transitions from feature phones to smartphones, the dynamics of game play are also shifting towards a higher quality experience," said Mark Donovan, senior vice president for mobile at comScore. "As a result, we can expect to see a profound increase in adoption of this activity, both in terms of audience size and overall engagement."

The better user experience on smartphones is reflected in heavier game play, according to comScore. Smartphone owners are more than three times as likely as regular phone users to play games on their device at least once a month. People with more sophisticated devices also procure more games, with 27.3% having installed at least one game compared to just 5.6% of feature phone users.

Smartphone users are also more likely to play a wider variety of games because of the broader capabilities of their devices. The top three game genres on smartphones were arcade puzzle games, at 12.9%, followed by card games (11.9%), and word or number games (11.4%). Hardcore games like racing, sports and action-adventure titles also had much higher adoption on smartphones.

When it comes to advertising in mobile games, marketers have already focused their efforts on devices geared to displaying rich media ads like the iPhone Android-powered phones. And mobile ad networks such as Greystripe have built a business specializing in serving high-impact ads in games played on smartphones.

Apple's launch of the iAd mobile ad platform last week should further encourage advertising in games and applications on the iPhone and other Apple devices by offering a wide range of creative and functional options for ads.