Karthik Bala, CEO of Vicarious Visions talks to us about the next instalment of the Guitar Hero series, which is being developed for the first time on the Nintendo DS.

We're the development team behind the upcoming release of "Guitar Hero: On Tour" - the first ever Guitar Hero game for Nintendo DS. Over the next few weeks, we're going to be talking about the rollercoaster ride we've been on this past year in the development of the game. It was a very unusual project to work on and we wanted to share some of our experiences with you.

The game actually started out over a year ago as an idea that some of our handheld guys were batting. The question was, "would it even be possible to bring the Guitar Hero experience to portable form?" That question quickly led to the major aesthetic challenge we needed to solve, “How do you recreate the essence of Guitar Hero for a portable without making everyone carry around a full size plastic guitar?”

We all thought it was crazy... and so did the guys at Activision and Red Octane. But we wanted to give it a try as a research project. Worst case, it wouldn’t work and we would learn a bunch of stuff and we move on. :)

To Activision/Red Octane's credit, they gave us the breathing room to experiment for a few months. The team built a *lot* of prototypes. Some were ridiculous... others a total disaster. But a few were promising. We'll be taking you through the prototype process in the next couple of weeks.

What became evident was that we were NOT going to recreate the exact same Guitar Hero game as console in portable form. Why bother? Having a full size guitar for a handheld makes no sense. So we weren't going to do that. Maybe we wouldn’t even have a guitar at all…

I still remember the day when some of the guys were standing in front of my office with giant grins on their faces. I knew these guys were up to no good. :) That's when they showed me a “Frankensteined” GBA cartridge with exposed wiring, switches and electronics plugged into a DS. The game prototype had a note highway, with the peripheral activating the gems on screen.

It was a breakthrough. We've never released a picture of the original device we built. Here it is:

Click for larger image

Yes, it had 3 buttons. But it proved the idea. We took it to Red Octane and their hardware guys (who are really friggin’ smart) went forward fleshing out the design.

There were a lot of challenges on the project – the user interface, peripheral design, graphical fidelity, audio compression and quality, storage space, multiplayer and more. In the coming weeks, you'll meet the team and how they tackled these problems. It was rough sailing on this project, but we had a determined team of core gamers/developers who had their minds set on one goal: Creating a unique portable music/rhythm game that uses the Guitar Hero mechanics and aesthetics.