Here's the thing about Nintendo 3DS: even if it didn't offer 3D, you'd still want one. It's a new DS with hugely improved graphical performance - eclipsing PSP and getting close to Wii - a beautiful widescreen display, and an excellent analogue controller.
Its 3D screen (and camera), however, elevate it from a must-have games machine to a must-have consumer device of any kind. It's not perfect - there's no doubt that there are more flawless ways to view 3D out there. But it works without glasses, in your hands, in any lighting conditions - and works very well. Its simplicity and immediacy are devastating, and in their way make it more exciting and impressive than any other 3D experience you can have.
The screen needs to be viewed absolutely head on - tilt the 3DS just slightly to one side or the other and the image on the lenticular screen suddenly fractures into two shimmering overlays. With a handheld device, obviously, this isn't really a problem, although the machine's motion-sensing controls (which we weren't able to try) will have to be employed with care. There's definitely an optimum distance between your eyes and the screen if you want to view the sharpest 3D image, but you'll find you adopt this automatically without even thinking.
The 3D image has perhaps a little less background depth than the current cutting edge of stereoscopic 3D, but the beauty of 3DS is that the effect is greatly enhanced by the simple fact that you're holding it. Objects in the foreground, suspended between your hands, assume a reality they wouldn't projected on the far side of the room. You feel as though you can touch them.
The 3D works noticeably better with bright, colourful images (good thing it's a Nintendo machine, then). Dark, high-contrast scenes produce slight "ghosting" - like an imperfect analogue TV signal - that is a bit distracting, although it far from ruins the overall effect.
Nintendo's stroke of genius - the company once again showing its gift for lateral thinking in hardware design - is the 3D slider, allowing you to adjust the strength and depth of the 3D effect. You'll usually want it on full, but the subtler 3D effect with the slider set halfway is surprisingly lovely, and you might want to adjust it a little depending on how far the 3DS is from your face, or on what your own eyes find comfortable. And of course, it means you can turn 3D off altogether. It wouldn't occur to most other technology companies that sometimes you will simply prefer to view images in 2D - but you probably will.
Nintendo has a wide range of very brief 3DS demos to try at E3. Some are video, only one is fully interactive, while most are semi-interactive in-engine trailers and model-viewers. You can also try using the device's 3D camera.
The 3DS' presentation of movies - I watched a trailer for How To Train Your Dragon - is crisp and smooth, but the 3D effect is relatively subtle when compared to graphics generated by the machine itself. These are unbelievable. A Metal Gear Solid trailer following Snake through dense jungle vegetation and across a vertiginous rope bridge was breathtaking.
Another demo had a series of Nintendo models to view which you could pan around using the 3DS' analogue slider. Static scenes from New Super Mario Bros. Wii and Super Mario Galaxy were amazingly solid and tactile - and also happened to demonstrate how easily capable the 3DS is of doing justice to models from Wii games. A statue of Link was, if anything, more richly detailed than that in the Skyward Sword Wii demo running in the same room. But the best of all was an image of Pikmin standing amid tall plants; moving the view around this miniature diorama left me speechless, drawn into the small screen in my hands.
The new Kid Icarus game wasn't playable, but the in-engine trailer made sense of this rather odd - if fan-pleasing - choice of launch game. Fast, into-the-screen flight action is the perfect high-impact demonstration for what 3D can do in games. The only fully playable demo was for Nintendogs. I could interact with a silhouette of the puppy on the touch screen while watching the 3D image above, petting it and throwing a boomerang or tennis ball around a spacious, well-lit room. It was less immediately showy than some of the other demos, but had a profound solidity to it.
The machine's 3D camera is no high-resolution photography tool, but it is a delightful toy. The images produced are a bit fuzzy but it appears to cope well with a range of lighting conditions, and it's hard to imagine the novelty of the 3D effect on the images you snap - or view live with a remarkably good frame rate - wearing off. You can adjust the focus and 3D depth.
As for the hardware itself, the 3DS is almost exactly the same dimensions and weight as a DSi and is instantly familiar to hold. It feels as solidly constructed and ergonomically comfortable as you'd expect of a Nintendo machine. It has bevelled edges and a graphite grey finish that give it a modestly futuristic look, while the top 3D screen and its pure black surround are under a single glossy surface - an iPhone-style presentation that looks great and really makes the image pop.
You could say the analogue slide control was like the PSP's, but that would do it a terrible disservice, frankly. It's the same concept, infinitely better realised. The spring is much looser, the very slightly concave surface holds your thumb well and the positioning is perfect. On the demos that allowed you to use it to rotate models or pan around the scene, it offered precise and smooth control. The d-pad beneath is now a little out of the way - it was under the joint of my (long) thumb - but will be nice to have for menu selection.
The face buttons are exactly similar to a DSi's, while the left and right shoulder buttons are slightly smaller. Between them on the back of the unit is cartridge slot that seems wider than that on previous DS units. The left side of the console has a volume slider and an SD data card slot, the right side a wi-fi switch, and there are Start, Select and Back buttons - under a smooth surface, but slightly raised and clicking when pressed - below the screen. The 3D slider is small and it must be said slightly fiddly, but its positioning on the right of the top screen is very easy to reach. A little green "3D" appears when the effect is turned on.
To hold one is to want one. It might not have the luxurious feel of an Apple product, but through a few subtle design choices Nintendo has produced a device that shares all the friendly and reliable qualities of the DS family whilst adding an edge of technological cool.
And that's before you switch it on and see that screen, and get sucked into the private world suspended in your hands. Is it just a gimmick? Maybe so, but it's a magical, irresistible one, backed up by hardware that would be a great improvement without it, and in a compact and fuss-free form that sails past any other consumer 3D products in terms of accessibility and comfort.
We need to know how much it will cost, of course, but on this showing Nintendo has not only reinforced its dominance of handheld gaming but shot to the front of the queue to own the a burgeoning new entertainment market. Nintendo 3DS is the mass-market 3D device. It's that simple.