The entire market was worth ¥192 billion (US$2.4 billion), down from ¥228 billion in the equivalent period of 2010, said Japanese publisher Enterbrain, which tracks the gaming market.

During the six-month period, sales of software dropped just over 20 percent and the industry failed to release a single game that sold more than a million units, which is typically the sign of a hit game in Japan. Last year, four games sold more than a million copies each during the first half.

The best-selling game of the half this year was Capcom's "Monster Hunter Portable 3rd," which sold 968,269 copies. The software launched on Dec. 1 last year and racked up sales of more than 3 million copies in the few weeks before 2011 began.

The number two game of the first half and the best-selling new game of the period was "Dragon Quest Monsters Joker 2 Professional" from Square Enix, which launched on March 31 and sold 469,469 copies, said Enterbrain.

On the hardware side the Nintendo 3DS, which launched on Feb. 26 in Japan, was the best-selling device. Nintendo sold 1.15 million of the handheld gadgets during the first half.