Nintendo unveiled a highly-sensitive motion controller add-on for its Wii system as it seeks to capitalise on its position as the global console leader.
At the E3 games conference in Los Angeles, the firm showed off its Wii MotionPlus, which it promised would add more realism and depth to games.
The company has sold more than 10 million Wii consoles and 70 million DS handheld machines worldwide.
Rival Sony has announced a larger capacity version of its PlayStation 3.
At a later press conference, Sony unveiled a film download service and an 80-gigabyte hard drive version of PS3 for gamers in North America.
Nintendo president Satoru Iwata said innovation was key for the company.
"Even if it is revolutionary sooner or later, people become tired of a new form of entertainment," he said.
Addressing the rapid turnaround in Nintendo's fortunes over the last two years, Mr Iwata admitted that the success of the company had taken even staff at Nintendo by surprise.
Referring to the success of the Wii, and peripherals like the balance board, he said: "Everyone had a pessimistic view of Nintendo in 2003.
"Even Nintendo employees could not have imagined that five years later the market respond so quickly that we could sell millions of bathroom scales around the world."
Mr Iwata, who was speaking to media at the Kodak Theatre in Hollywood, said the firm's success had resulted in a paradigm shift in the industry, with hardware sales growing in periods outside the traditional high spots, and software titles like Brain Training and Nintendogs having two-year life spans on retail shelves.