This isn't the first iPhone game that's been accused of causing motion-sickness, and it probably won't be the last. It's a side-effect of an immersive experience, so in many ways Rock'n'Roll could reasonably - and without any intended criticism - sport the slogan, "So good it'll make you puke".
A bizarre story about a kidnapping and the collecting of scattered musical notes is enough to start giving you the spins, but give its cartoon comedy a shot. As it goes, Rock and Roll are at the beach discussing the sweltering heat. This prompts a flick on of the air conditioning. Meanwhile, the Evil Sky Spirit is rejoicing on his mountain of power, as his new Guitar Villain game has arrived. As he begins to rock the house down, the generator explodes and scatters his musical notes across the island. Rock is kidnapped to force Roll to scour the island gathering up the notes to appease the Evil Sky Spirit and free Rock.
The opening cut-scene is quite superb, and really sets Rock, Roll and the Evil Sky Spirit up as amusing, lively characters. Roll essentially stays in the centre of the screen, while the devilish mazes rotate around him. The objective is simple in principle, but difficult to achieve - tease Roll around the level and pick up a required number of musical notes littering each maze.
There are two methods of control, which make a big difference for unshackling the enjoyment of Rock'n'Roll from the more aggravating aspects of play. Tilting the handset in accelerometer mode rotates the maze - the further you turn, the faster it spins. This initially seems like the most practical way to control Rock'n'Roll, but in practice you lose control so often the game struggles to maintain its endearing visage.
Switching to touch control really improves matters, however, as the maze feels to be much more under your command when rotating and flicking it with a finger. The extra precision is vital not only to a successful level, but to keeping the game from overbalancing into frustration territory.
Disorientation is intended here. Playing Rock'n'Roll on the bus, for instance, is likely to make your head spin so fast you'll think the fare's reasonably priced, while taking to the labyrinth when tired is such an intensely immersive trip it can fully energise you through sheer kinetic induction.
Talking about Rock'n'Roll in this way will have a different meaning for different people. If you're a roller coaster rider, and still play on the swings when you take the kids to the park, it'll sound like a compliment. If, however, the opening credits to Doctor Who make you feel bilious, this probably isn't going to be the kind of gyratory encounter you'll want to have with an iPhone. Either way, for such a lighthearted game, Rock'n'Roll is remarkably addictive, and that's never a bad thing when it comes to innovation.
It's always great to see a game designed specifically for a system, rather than being a conversion warped to work in a foreign environment, and Rock'n'Roll fits that category very well. Puzzle fans will find a lot to enjoy, and the cartoon styling will undoubtedly win you over. But be warned: when it gets irritating (and it will), put it down for an hour lest your iPhone find a crack in the screen.