"We began prototyping ideas for Guitar Hero on DS in early 2007. We quite frankly didn't know whether it would be possible to bring the core essence of the franchise to handheld and have it actually work. It was 20-something gameplay prototypes that were built, all trying different mechanics and uses of the hardware. Some were pretty cool, others were total disasters!

At some point, we hit upon the idea of creating a peripheral that would have the fret buttons plugging into the GBA slot of the DS. We ripped apart an old GBA cartridge and did some electronics work on it to rig up a prototype device. As awkward and crude as that prototype was, that's when we knew we were onto something. We figured that attaching a full-size guitar or even a mini-guitar would be too awkward to play on the road, hence the design of the more compact Guitar Grip, which gives you the tactile sense of the fret buttons, with the touch screen depicting the strings of the guitar."

Karthik Bala, CEO of Vicarious Visions.