Shigeru Miyamoto says Nintendo is still in the process of designing the controller for its next-generation Revolution games console.
"We're at a stage where we're adding and removing various kinds of functions, which has been very fun," he said at a business strategy conference in Japan.
The company wants the control to be basic enough to fits it "All-Access Gaming" philosophy, which it hopes will encourage non-gamers to try out Revolution and its current line of handhelds.
President Satoru Iwata unveiled Revolution, which will be released next year and includes broadband access to Nintendo's entire back catalogue of software covering 8-bit right through to 64-bit as well as GameCube backs compatibility, at the company's pre-E3 press conference in mid May.
Adding his thoughts at the meeting this week, Iwata said: "We expect that you will be surprised with the Revolution's controller," in comments reported by US website GameSpot.
Further Revolution revelations should be made before the end of 2005, Iwata had earlier said.