Put this disc into the Wii and a strange transformation happens. The small console turns from a family-friendly, happy-clappy love house into a sinister, face-smashing, motherf*****g murder machine.
Madworld isn't messing about. Jack, the main character, turns up in a city (Jefferson Island) full of mental bike-like terrorists and, with you in control, he murders the lot of them in the most gruesome way possible.
The more inventive you are with your killing, the more points you get. Lucky then, that for no obvious reason at all, the city streets are littered with spinning blades, spike-covered walls and bins with blades on their lids.
But what's the object of the game? Sega described it to us as a "new-age Streets of Rage". You're let loose to roam free in a city district killing terrorists with the aim of building up a target score without dying.
Reach that score and you activate the boss battle. Win that and it's on to the next level. That's the simple premise behind a whole lot of blood-stained fun.
It's all about mixing up your kills. You can kill an enemy by slamming him chest-first into a huge spike on a wall (several times over), but if you shove a tyre around his body, headbutt him in the face, slam a pole through his brain, THEN bat him through the air into the spike on the wall, the game will love you more.
We kicked a guy to the ground, slammed an explosive barrel over his head and lobbed him at a group of three other goons. He exploded, the impact sending his mates flying into surrounding spinning blades. Red filled the otherwise black and white screen... and we laughed.
What's brilliant is that, as sinister as this all sounds, the whole scenario is dressed in a TV game show theme. Bloodbath challenges - special mid-level bonus challenges - are introduced like rounds in Supermarket Sweep.
But instead of a camp presenter you get a mean-looking dude who calls himself the Black Baron. He takes to the stage, swears loads, before his female assistant turns up and smashes him in the face with a spiked bat.
The Bloodbath challenges are sweet. We saw two in the level we played - one where you have to throw as many goons under a giant spiked 'Death Press', which slams down and liquefies bones.
The other is a bloody game of human darts; you smash dudes with a spiked bat into a giant dart board, aiming their splatting corpses for the bull's-eye in the middle. Hilarious.
Also during stages you encounter mid-level bosses - like the eight-foot Minotaur bloke with a massive dual-blade chainsaw that run up on us. These battles are a little more challenging because, whereas you can punch, kick, slice and generally mutilate the common enemy with little effort, these geezers don't take it sitting down. He'll slam you across the street.
Part-way through our battle we activated a Gears of War 2-style chainsaw clash (yes, Jack has one too), which has you shaking both the Wii Remote and Nunchuk to win.
This is one of the subtle but neat ways the game uses the Wii Remote and Nunchuk. Normal movement is done with the analogue stick. Hold A to grab someone and you throw them with a flick of the Remote, or headbutt them with a shake of the Nunchuk.
B activates your chainsaw, although if you wave the Remote in a slicing motion you can dismember entire groups of enemies, who fall to the ground pissing blood from the hole where their heads used to be.
Rip a pole out of the floor and a downward swipe with the Remote plants it into someone's face - all the motion controls correspond in a simple way to what's going on on-screen, enhancing the visceral feeling of the game with out ever feeling awkward.
Madworld is one strange game. We've only played the first level, but we already love its comedy spin on graphic violence, with its TV game show theme, custom hip-hop soundtrack and foul-mouthed commentary. This is absolutely not for kids, But you knew that already.
Our exclusive screens below show Jack riding a bike through the street, so we know there's a lot more Sega's keeping under wraps too. C'mon Sega, give us some more.