It's a strange thing to be known for, but A Plague Tale: Innocence [official site] will almost certainly be That One Game With The Brilliant Rats. As soon as footage starts to spread around the internet, it's the rats that people will settle on because they are the entire point of the exercise. With all apologies to the two kids who are the actual protagonists, sneaking through a plague-ridden medieval French city and avoiding both inquisitors and rats, it's the swarms that steal the show. Both as a game mechanic and a technical feat, the rats are king. It makes Dishonored look like a petting zoo.
Watching a slice of Plague Tale, played by a developer, reminded me of seeing the Mardi Gras crowds in Hitman Blood Money for the first time. Games often avoid depicting large groups of moving characters, preferring to treat crowds as a single entity rather than a larger entity made up of many smaller but discrete elements. I loved that in that Murder of Crows level, a gunshot would cause groups of people to separate, splitting into their own unique patterns of panic and escape.
A Plague Tale, in its current form, puts its big idea right on the menu screen. A swarm of rats, each one moving dynamically, are feasting on a corpse. You can see them squirming up and around one another, nibbling and biting and fighting for space. And then, when you press start, a carriage rattles past in the street outside the building where the body is lying and its lantern sends a pool of light splashing through the window. The rats peel away from the light, scurrying and scratching, and then slowly inch their way back to the feast once it has passed.
It's grotesquely gorgeous and explains the game's central conceit extremely well. You play as two children, though there's no evidence of a smart Brothers: A Tale of Two Sons style control system at this point. It looks like you'll always, or mostly, be in control of Amicia, the older of the two, or whether you'll also control tiny little Hugo who is about six years old. Amicia is either pre-teen or barely into her teens, but she seems capable enough, at least in the brains department, outsmarting the chaps who are hunting her and her brother. It's a stealth game, based almost entirely around light rather than sound.
Rats don't like the light, so the darkness is often a sea of teeth and eyes. Portable light sources keep them at bay, but are hard to come by, so you'll need to stick to what light there is in the environments, while destroying the lanterns and torches that the inquisitors carry. When you do, they're soon covered in rats, screaming and devoured. Grim.
The small chunk of the game I saw might not actually be in the game at all, with release possibly a year and a half away or more, but as a technical demonstration it was impressive. At one point, rats pour through a church's windows like streams of oil, flooding the floor and lapping against the flicker of torchlight that protects the protagonists. They're fluid, like a particle system with teeth and claws, and the way that they writhe and surge adds an element of horror to what might be fairly conventional environmental light-based puzzles.
It's too early to know whether the game will live up to its rats, but I do like seeing a mechanic directly tied to exciting tech. The historical setting has clear elements of fantasy, not least in the rats themselves, but will be mostly grounded in reality, and if the environments are depicted half as well as their inhabitants, it'll be a beautiful game if nothing else.
Side note: developers Asobo worked on a game based on the Pixar film Ratatouille and that amuses me.