At first, a portable version of the Guitar Hero series seems a far more legitimate way for Activision to bang out more SKUs than its cash-in "Rocks the 80s" and "Aerosmith" titles. Just imagine, rocking out on a train full of grey-faced commuters, shining brightly from your cramped little corner with the flaming glow of rock!

The grim reality is playing this game in close quarters with strangers is beyond the confidence of most. In fact I'd even call it freakish. Embarrassing. It's not just the handycam-like "Guitar Grip”, the loud tapping of your pick-stylus or even the cumbersome wrist angles that make the game so embarrassing. It's the fact that even a handheld Guitar Hero has the ability to make you head-bang and foot-stomp like a club punter. There's a good reason Activision didn't include a proper guitar controller. You'd back-hand some old lady in the face pulling windmills.

It's true: activating star power is something that should only be done in shelter of one's own home, where any company is familiar and hopefully dosed with social venom. So it follows that the only types of people who should feel the need to take Guitar Hero around with them are those who have no console of their own, or those who are in fact children.

What's more, I'm yet to encounter an adult who upon publicly reaching an unskippable portion of a DS game that requires interacting with the mic doesn't simply close the lid and stare shamefully out the window. Kids, on the other hand, can run around shopping malls in their underwear with a face full of ice cream.

Anyway, let's hope that this game was designed for kids, because for anyone with decent sized hands, Guitar Hero: On Tour will cause some serious cramps. And I don't mean a mildly uncomfortable burn that can be relieved with a quick shake of the wrists. After a decent session, you'll feel like you've done 200 reps on one of those grip-trainer devices metal-heads keep in the drawer next to their skull rings and string lubricant. I've read various remedies for the cramping, like lying down with the DS on your chest. My personal solution is to cradle the DS partly with your picking hand, but I digress. Advice like this shouldn't be necessary.

Maybe I'm being too harsh - after all, the "Guitar Grip" only costs a $15-$20 premium on your average DS game. The pack includes an adjustable grip, a pick stylus and a game case. It even includes those cute little stickers for customising the faceplate, as well as an extender to make the peripheral fit better into the DS Phat.

Sadly Activision have chose to omit one essential accessory: a folded up blue post-it note, much like the one I have shoved into my DS's GBA slot to stop the stupid thing falling out at the slightest touch.

I'm not exaggerating to say that the pressure required to depress a piano key will dislodge this thing from its slot. Even worse, when this happens it's not a simple matter of pushing the grip back in and continuing to rock. No, it's a power-off and restart situation that will no doubt have the more excitable fake-guitarists trashing a hotel room. Or living room. To be fair, the DS Phat attachment fits nice and snugly, so there's one more thing the original design does better besides scratching easier and looking crappier.

Wow, all that and I haven't mentioned the gameplay itself. Well, it's pretty much Guitar Hero with four buttons. That may sound like it makes things easier, and you'd be right in thinking so: I play through Hard mode from start to finish without failing, cramps and all. But anyone that says that Expert mode is too easy is a liar and probably cruel to animals. It's a jarring jump in difficulty.

The major differences in the play mechanics are all touch screen based. To play notes, you now strum an on-screen guitar with the pick stylus. The whammy bar is activated by holding down the stylus and moving it on the screen, while star power can be activated by blowing on the mic or pushing any face button. I also happily discovered that during faster passages it's possible to simply scratch the stylus up and down without lifting to simulate tremolo picking. It's definitely easier on the hands.

The 28 songs will certainly seem limited to those used to downloadable content, but obviously we're dealing with issues of cartridge space here. Signs of space saving abound, from the compression of the songs themselves to the fact your fictional band has become a three piece with a singing bass player. They've also taken a poppier edge, choosing to pepper their set with tracks by Maroon 5 and Smashmouth. Stay your misguided accusations of selling out though, friends: the vast majority of tracks are the same fret-abuse you've become accustomed to.

Activision also managed fit in a guitar duel mode, which most Guitar III players will be familiar with. The big additions for the handheld come in the form of mini-game "attacks" which can be earned by playing sequences of notes. When performed, sometimes your hapless opponent won't be able to see their guitar until they sign a T-shirt, blow out a fire, or repair a string. It can be more annoying than fun, but at least it earns the game another play through.

Further extending the life of the game are of course the practice modes, which again include guitar and bass, as well as multiplayer, which lets you play face-off, co-op and the aforementioned guitar duel.

It's hard to argue that this isn't a startlingly complete package for the price. If you're under 14, or some unfortunate pituitary disorder has rendered your hands miniscule, you can't really go wrong with Guitar Hero: On Tour. Just make sure that when you're touring, it's somewhere devoid of other people and their pitiless, judging eyes.