Guitar Hero has a spangly guitar, Dancing Stage a blinking dancefloor and Gran Turismo a steering wheel that, when you push it, pushes you back. Samba De Amigo has tequila-fragranced maracas [sniff... Lies! - Ed], Maestromusic an erect conductor's baton and Steel Battalion a huge cock-off robot dashboard. These are all videogames that have seen their manufacturers carefully pipe plastic into (mostly) recognisable real world shapes: an effort to normalise that most alienating abstract interface - the videogame controller.
The DS's stylus is already a real-world interface. Anyone that has held a pen or chalked a board or drawn pictures in the sand with their finger already understands how it works. And so, the leap of imagination Lost Magic requires you to make - that your stylus is a magic wand with which arcane symbols must be traced to unleash magnificent physics-bending spells - is pleasingly unnoticeable. Indeed, it's such an obvious move, and one sure to be replicated on the wand-like Wii controller in one form or another, that you wonder why so many Potter tie-ins have failed to make use of it.
At least, that's what you wonder while tearing the wrapping off the box. In-game it becomes increasingly clear that this is a tricky gimmick to make good.