The last time Nintendo decided to change what you’d expect from a handheld console they added a second screen to it and created the Nintendo DS. It may have seemed a risky move at the time but it’s now the biggest selling handheld with over 129 million sold across the world.

Six years on and this time they’re making one of those screens 3D, but there’s more to it than that. Unlike when you go to the cinema, the only need to wear glasses is if you are short-sighted.

Like with films the big question is “why do we care about this stupid gimmick because it’s just a visual toy and doesn’t add anything” and the answer is “shut up, it’s brilliant in games.”

Unlike in the cinema, the smaller screen of the Nintendo 3DS means that the visual effect isn’t overwhelming but really adds (excuse the pun) some depth to the imagery. The bright, vibrant screen means that games like “New Super Mario Bros.” really come to life and look more engaging without being distracting.

The power of the 3DS itself has been boosted compared to the old models making it more than a match for the PSP, with demonstrations showing models based on “Super Mario Galaxy” and “Super Smash Brothers” looking gorgeous in 3D scenes on the 3D screens.

The changes do improve playing games such as with “Nintendogs + Cats”. When the dog jumps up at the screen to say hello and then runs off to follow a thrown Frisbee it feels much more vivid but the effect also feels completely natural.

The bottom screen is a touch screen as before but is just 2D otherwise it would just be confusing to start touching things as they come out of the screen and would break the illusion.

Games like “Pilotwings” also benefit really well from the system’s capabilities. When flying a plane or jetpack round the small island the added illusion of depth allows you to make more accurate decisions based on distance.

You’re not just guessing how far something it because of size – you’re guessing because you can properly see how far away it is. It may sound small but does make a huge difference, especially for people who can find running around in 3D games environments confusing.

As well as the new screen, other new features include a “slide pad”, a flat analogue stick to control games with your thumb, and a pair of cameras on the front of the console so you can take photos in 3D. This is obviously to add something interesting and new to photography and not something that will be quickly exploited.

The Nintendo 3DS creates the same 3D effect as films by having two images of one scene but produced at slightly different angles. Each eye sees a different view and that creates the stereoscopic effect and it works absolutely perfectly.

The smartest thing about the system is that you can control the strength of the 3D effect and even turn it off completely. It’s not hidden in menus but is actually controlled by a small sliding switch on the side of the system.

At any point when using the 3DS you can move it to increase or decrease the depth to a level that’s comfortable to you so if it does get a bit much for your eyes you won’t lose anything at all.

The new dimension genuinely adds something more to the games and it works perfectly. By having all the technology in the one system means you get around many of the issues you’d have with 3D on TV like cost, content, lots of different bits of equipment – and best of all, without looking like you’ve been rejected from a ‘80s music video.

The Nintendo 3DS will be released in Japan on February 26th and is expected to be released in Europe before the end of March 2011.