The boy is not strong, but he's light and quick-footed, and can shimmy up chains, navigate ledges and run across crumbling beams in much the same manner as the stars of Ico and Shadow of the Colossus. As in the latter, he has a stamina gauge limiting his ability to cling, leap, balance and climb, which appears in a hand-drawn and animated scroll above his head when he performs these actions. The controls and platforming style appear to be very similar to those in the team's two previous games.
The boy will encounter enemies, but being tiny, unarmed and dressed in a light toga, he's not strong enough to tackle them in direct combat. When he encounters a truly frightening guard grunting and clanking around in black plate armour, Ueda says that the best way to get past him is by stealth – crouching and creeping along walls.
There are other ways to lure, outwit and outrun the slow guards – who can't climb in their heavy armour – but if caught, you only have a short time to wriggle out of a guard's grasp or it's game over. Though the boy may learn some tricks, Ueda says, it's the powerful Trico who will be attacking enemies in The Last Guardian, and for the most part the player is not directly involved in combat at all.
At the end of the demo, the boy finds himself at the top of a tall shaft crossed by slender beams and bridges, with Trico visible far below. He calls to it with a wordless, echoing cry, but the creature doesn't hear, or doesn't want to. "Normally he jumps straight up. Seems like he's in a bad mood today," chuckles Ueda.
It's an awkward moment, but at least it proves Ueda's talk of a free-spirited, recalcitrant artificial intelligence powering the huge beast. This will be difficult to fine-tune correctly if Team Ico is to preserve Trico's unpredictability and electrifying presence – as bizarre as it looks, it's impossible not to regard Ueda's creation with awe – whilst making him biddable enough not to frustrate.
After half a minute of calling, Trico takes notice, and thunders up the shaft in a series of crashing bounds that shake the stone, finishing by towering above the small boy and lowering its huge eyes to his. "You'll notice the very drastic difference in dynamics of how the boy can manoeuvre versus Trico – the gameplay will be a combination of using both of those skills to your benefit to make progress," summarises Ueda, blandly.
If you're looking for the key to Team Ico's brilliance, maybe that's it; a guileless willingness to keep things simple and let them speak for themselves. The great mystery is that there's no mystery at all. The Last Guardian is a story about a small boy befriending a giant animal, and that's all it needs to be.