TOKYO – The runaway success of an iPhone game created by two brothers on a laptop is pressuring video game makers Square Enix Holdings and Capcom to reboot strategies and appeal to mainstream players.

New York-based Lima Sky struck gold with “Doodle Jump,” a game downloaded 4.7 million times from Apple’s iTunes Store, ranking No. 4 among the top 100 paid applications for the iPhone, iPad and iPod Touch. The 99-cent game has more than 170,000 Facebook followers.

Making hit games for Apple’s mobile devices has proved difficult for major Japanese publishers, which typically devote millions of dollars, large creative teams and several years to develop games. Square Enix has no entries in Apple’s top 100, while Capcom’s 99-cent quiz game ranks 98th. Activision Blizzard, the world’s largest video game publisher, has two.

“The success of Apple’s devices is the biggest source of concern in our packaged-software business,” said Haruhiro Tsujimoto, president of Capcom, Japan’s fifth-largest game maker.

“Demand for the iPhone has spread to the casual-user demographic, a trend likely to be amplified with iPad’s release, making it a gaming platform in its own right and a market that cannot be ignored.”

The top-selling paid application in the iTunes Store is the 99-cent “Angry Birds” by Rovio Mobile Ltd., a Helsinki-based developer with 17 employees.

Igor Pusenjak, 34, created “Doodle Jump” while teaching part-time at Parsons The New School for Design in New York. His brother, Marko, 32, handled programming on a laptop. They formed Lima Sky in 2008 and released the game in April 2009.

The title, in which players guide a four-legged creature up an endless series of platforms, was the most-downloaded paid application in the United States in April and topped paid game rankings in January, according to Utrecht, Netherlands-based market researcher Distimo.