Their essential mechanics are about as old as games themselves. Speaking about Rez's development process, Mizuguchi reveals that the core shooting was what came first. Before all those layers of visual and aural feedback, Rez was born as a simple, bare-bones shmup.
"It was a very original, unique approach, I think," he says. "With Rez, I asked the artists not to design first – that was very philosophical, maybe, but we were making a game, and we needed to find the game mechanics first. We came up with something where you shoot an object and spread particles with simple sounds. There was no gorgeous visuals, no gorgeous sound yet. That was what we made first. And if playing that on its own feels good, it's worth pursuing. That kind of approach is very important.
"Only after that, then we started to think about how we could make it feel better – what kinds of colours, what animations and movement, what sounds feel good. It was the product of much trial and error."
This is the same approach that Q Entertainment used for Child of Eden. They had to spend an awful lot of time trying to get the core Kinect control working in such a way that the lag didn't completely ruin the experience of directing music with your hands. Once that problem was finally out of the way, things started to take shape, and Child of Eden started to look like the dizzying sensory overload that it is now.
"This isn't easy, you know, this kind of project," Mizuguchi reminds us – something that's not difficult to believe. "Ubisoft is a publisher that understands entertainment with art elements," he says. "Of course a game is entertainment, but sometimes we need a new artistic approach, a very creative approach... I think this is a very creative adventure for Ubisoft. I was very impressed that they were so aggressively creative in attitude. And they respected that in us, also."
When I ask him if there are any other developers he believes might think along the same lines as his own studio, Mizuguchi's first answer isn't surprising. "Harmonix," he says. "They do this kind of thing too, and they're very good." But his other answers are rather less obvious. "There's Q Games in Kyoto too, we're very friendly," he says, referring to the studio responsible for PixelJunk, which also happens to have an almost identical name to his own outfit. "And Media Molecule, too."
Given the creative variety of his own output – Space Channel 5's mad galactic Michael Jackson tribute, Lumines' deceptively calm-looking score frenzy, Rez's electronica matrix and Child of Eden's organic, evocative space opera – it's perhaps not surprising that Mizuguchi sees some shared ideology with the makers of LittleBigPlanet.
Child of Eden is the closest thing he's ever done to a direct sequel to Rez, and the fact that it's still so very different from anything we've seen before suggests that it will be a long time before he's out of ideas.