Perfect games, argued Ishida, are boring. In Space Invaders Infinity Gene, for example, he originally experimented with making the invaders more colorful (which you can see on the right in the shot above). But that look made the game "look too 'normal,'" Ishida said. "It didn't really stand out enough for us." He decided to go back to the white coloring of the original invaders, and that helped give the game a unique look.
Those graphics may not be the most aesthetically pleasing to the eye, but Ishida said that helps more than it hurts. "You need a little bit of that quirkiness," he told the crowd, "so it captures your eye and your attention, and it leaves that impression."
And that attention leads to curiosity, which Ishida said will really make a game shine. "People will find that curiosity and they'll want to find out where that curiosity is going to take them," he said. Developers obviously don't want to turn off an audience with disharmony, but Ishida said a great game should have "just a little touch -- something that will trigger someone to think that maybe there's a little more that I need to seek out."