The Master of Synaesthesia

"The concept is hope and happiness. That's what we pitched first," says Q Entertainment's Tetsuya Mizuguchi, sitting down after a Child of Eden demo to talk with us about his work in games so far. "It's like a spiritual sequel to Rez, definitely, but I wanted to have much more organic feel, not only digital, techno. I made it like a drama, a story, an emotional setting – it has songs, lyrics, words.

"The visuals are like moving textures, moving sounds. And the physics, too, looks like nature, like how particles spread with the music, and the changing of colours with sounds... If Child of Eden were darker, it would just look more like Rez."

Child of Eden is enough to bring out the poet in all of us. When you're floating alongside a shimmering space-whale, flinging musical bullets at it with your hands like an omnipotent cosmic conductor, until it coalesces into a ball of light that explodes into an enormous phoenix, it's difficult not to go all starry-eyed and start pulling together verses of praise. It's the first game I've seen in a long while that actually makes the hairs on the back of my neck stand up.

Mizuguchi is an able demonstrator. He understands exactly what makes Child of Eden fascinating to watch, holding back from theatrical hand-flourishing and letting the game speak for itself. Like all of his work, it's mesmerisingly synaesthetic. Your movements make sounds, which in turn make colours and light patterns that come together with the game's own beautiful visual and aural backdrops. The finished illusion of control over the sights and sounds makes you feel like a spiritual force of creation. It's like nothing else.

In terms of its actual mechanics, Child of Eden isn't so much a spiritual successor to Rez as an actual sequel. Your left hand is a snare-drum machine-gun, streaming weak bullets wherever it points. Your right is a paint-and-shoot laser, unleashed by flicking your hands. But Child of Eden's personality is very different; where Rez's wireframe worlds were spun from tension, darkness and ominous electronic sounds, Child of Eden is organic, joyful, luminescent.

Mizuguchi describes the concept of synaesthesia as his "life theme", a development mantra. He only reluctantly describes himself as a developer of rhythm games, preferring to think of his creations in different terms. "It's a new frontier, still," he says, talking about the mix of game mechanics, visual art and music that Rez and Child of Eden embody. "I still believe in the power of the sound, the music, to be emotional, to be a game in itself."

If you ask me, though, Mizuguchi's work is pure game. Trying to distance his works from that label and put them in the loosely defined category of "interactive art" does them a disservice. They marry the compulsive, trance-like euphoria of 2D shooters – particularly the Japanese art of the bullet-hell shmup – with the related euphoric qualities of music, and hypnotic light and colour.

They do what the best rhythm-action games do – send your brain into a happy pattern-matching reverie – but their way of doing it is entirely their own.

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.