SAN FRANCISCO--Fresh off a Best Audio IGDA award for Guitar Hero II, representatives from Harmonix, the developer of the game, discussed the issues encountered and lessons learned from building the game. Producer Daniel Sussman and senior audio designer Eric Brosius articulated new issues they encountered with level design and the thought that went into creating the Guitar Hero franchise.

　　Much of the focus of the panel was on how Guitar Hero II took a lot of lessons from the rest of the industry, but with Harmonix applying its own specific twists. For example, games often rely on repetition to build skills, then variation to keep player interest.

　　Brosius noted that in platformers, level designers built on this concept by letting the gamer do something familiar, then something new. "[But] when we do something with pop songs and rock songs, the artists who have written them have done a lot of the work for us."

　　In fact, the repetitive nature of pop and rock music worked to help develop the songs, the Guitar Hero equivalent of levels, Sussman argued. The musical structure of verse, chorus, verse, chorus, solo helped provide the structure that game designers often seek when trying to challenge their audience.

　　This also helped scale the difficulty level, Sussman pointed out, drawing comparisons to non-music games. "As a game designer, you're looking to bring people in at an easy level and then you throw all kinds of challenges at them as they improve."

　　Similarly, it was important that players could easily articulate the differences in difficulty. Guitar Hero helps them along by having only three possible notes on "easy," four on "medium," and all five on "hard" and "expert."

　　The design is made more difficult by the fact that the tools available to the developer on any specific song are extremely simple. "It's notes, long notes, and two notes at a time," said Brosius, in describing exactly what gamers could do on a level.

　　Earlier in the panel, a show of hands demonstrated that much of the audience had played Guitar Hero II and could appreciate the specific examples and songs that Sussman and Brosius used. The two capitalized on this enthusiasm by showing how song selection could be classified into different types.

　　"Unrelenting assault" was their name for songs like Foo Fighters' "Monkey Wrench" and Helmet's "Unsung." Featuring lots of persistent rhythms, physical gameplay, and the need for endurance, these songs differed from Blue Oyster Cult's "Godzilla" and Matthew Sweet's "Girlfriend," which focus more on verse and chorus bits. As Sussman described it, "You're always going back to the foundation, this bass line, then we throw in fresh things."

　　Some other classifications included "death match" (lots of sight reading and instinctive play), "ass kicker" (very physical, repetitive gameplay coupled with patterns that are physically hard to get), and the "boss song."

　　The boss song was especially noteworthy, Sussman said, because "just as it's important to have that first song, it's important to have that song that drives you crazy." In addition, it was interesting in that it broke so many tenets of level design. "I've never seen so many people die at 99 percent, because that's just f***ed up. It's just kind of mean. We get away with it because our songs are kind of short."

　　Their final classification was "set piece," the classic songs that people would immediately recognize like Jimi Hendrix's "Spanish Castle Magic" and the Police's "Message in a Bottle." Describing Boston's "More Than a Feeling," Brosisus said it "was a perfectly balanced pop song, with some simple emotional lines and the big long notes. That just automatically worked, and everyone just kind of liked it. Nobody thought people would like that."

　　The rest of the lecture was left for a short question-and-answer period where they described some of the changes they made in response to tester feedback, like adding a guitar solo to David Bowie's "Ziggy Stardust." No one had to ask the most common question though, what Harmonix was doing after Guitar Hero II, because the final slide had a bullet point: "We can't tell you what Harmonix is working on...hint: it's not Accordion Hero."