It is often hard for game developers and the production companies that back them to justify trying new genres. When existing styles of gaming are tried and true, those with the money don't want to back new endeavors that might lead to failure. But, once in a while a new genre will be tested and prove to be successful. Such was the case with the Guitar Hero series, which seemed awkward at first but quickly exploded into one of the most popular series of the past few years.
The latest iteration of GH proves this and has done Activision very well. In the first week of sales, they are citing figures as high as $115 Million, making it Activision and RedOctane's most successful title at launch. In a recent interview, the head of publishing for RedOctane, Dusty Welch, spoke to CNET regarding the series and why it had done so well.
It sheds some light on the reasoning they even choose such a genre, which was largely influenced by television. He cites parallels to Nintendo, and how they have been actively seeking to break out of traditional gameplay elements to entice people, if not by novelty than by uniqueness. It's definitely worth a read if you want some insight as to how it came to be and where they plan to go from here.