"There's no need to sell your furniture or move to a bigger house, but you'll want to clear some space so you can make the best moves when using Kinect."
That's the opening sentence of an email I received yesterday from Microsoft to mark the US launch of the hardware. There's an accompanying cartoon and it's all very "ha ha, geddit?" in tone, but behind the scenes some of the laughter will be nervous.
Space will be an issue for many with Kinect and Microsoft knows it. Which is why all the promotional videos seem to have been filmed in carpeted aircraft hangars. And yet if there's one group of gamers who should be prepared to call in the removal men, it's fitness freaks.
When Nintendo's Balance Board came in, chairs and tables went out. And having used the first two EA Sports Active titles, with all the lunging, thrusting, squatting, writhing, gasping and weeping that entails, in my tiny studio flat I ought to be as 'Kinect-ready' as the next person.
YourShape: Fitness Evolved isn't lying. Gone are the boards, Wiimotes and thigh straps of yore. It's just you and the imaginary fitness mat you just shifted half your furniture for.
Kinect could not be better suited to active gaming. It's no coincidence that five of the 19 'launch window' titles for the device are exercise-based. And it only takes a couple of minutes to realise that, on a tech level at least, YourShape leaves all previous fitness games behind in the changing room.
Ubisoft has exploited Kinect's real-time motion-capture abilities in what it calls Player Projection technology. Simply put, it sticks you in the game. The augmented reality effect is impressive enough – and if you don't like staring at your own body in startling detail you can apply a range of pleasingly dehumanising visual effects.
But it's when you begin your physical assessment that the penny drops. There's no guesswork with Kinect; no extrapolation based on where a game thinks your other limbs are – it's tracking your skeleton from head to foot.
For a fitness game this has a profound implication: no cheating. With the best will in the world, during some of the more savage workouts in EA's titles – rollerblade jumping squats, anyone? – the temptation and ability was there to cut corners when the burn became too much.
No chance of that in YourShape. If you're not performing an exercise exactly right, the game knows. And it tells you. Many exercises are split into parts so Kinect is used to assess, for instance, if your stance is wide enough, your arms are moving through the full range of motion and if you are moving in time with your on-screen instructor, whose moves you are attempting to mirror.
It's as unforgiving as a real trainer. But the positive flipside is, whereas with previous games there was too much guesswork involved to know if your technique was actually any good, now you'll learn to nail positions exactly to reap maximum benefits while maintaining correct form.
When you begin, Kinect scans your body to measure stuff like chest size, waist and hip line, arm and leg length. It's all very futuristic and exciting. The main things it can't determine that you need to input are age, weight and how frequently you work out (if at all).
After selecting an overall fitness goal, YourShape informs you it has created a personal workout programme for you based on your physical assessment. What that means is practice is that you'll find "recommended" tags applied to routines best-suited to your needs, while being told to avoid stuff that's not really applicable – and in fairness I have no yearning desire for "Perfect legs and butt".
Content is divided into three areas: Activities, Gym Games and Classes. The bulk of the exercises, including your personal programme, are found in the former, which offers routines that from "Sleeves busting arms workout" and "Skinny jeans workout", to plans tailored for women who've recently had a baby.
Classes are split between cardio boxing and tai-chi, with a range of progressively more challenging routines to choose from.
There are four mini-games to play in the "gym" area. In Virtual Smash you punch and knee blocks that appear before you on-screen, while also ducking a swinging pendulum on the hardest setting. The ruinous lag of the E3 demo has fortunately been tweaked here so, while not entirely eliminated, it's actually playable now.
Light Race creates a circle of panels around you on the floor. Segments light up at random and you have to stand on them as quickly as you can, so it's a bit like playing DDR while hammered without the insane tunes.