BurnBall

Inside every crayon box sits a gray crayon. As if begging not to be used, it offers no benefit to the casual colourer who seeks to scribble of vibrant hues over the lines. It's not like you'd shade the grass in gray or the colour the sky a murky tone.

At least you could colour in the backside of a first generation iPhone, leaving BurnBall to to the front. With its vivid gameplay, this tilt teaser has you fighting an evil genius who has taken your friends hostage, unleashed robots upon the world and drained the planet almost entirely of colour. Yes, Dr Gray comes from familiar stock.

Dr Robonik may look upon the game's plot with envy, but its the colour-coded play that would irk him with a its welcome simplicity.

Owing much to Windows wonder JezzBall, the game's only goal is to bring the colour back to the world. You do this by using the accelerometer to roll a ball around the screen. Each stage requires converting 75 per cent of the screen from gray to move forward.

It's possible to reclaim whole swathes in one go. Starting off in whatever colour already resides on the map (usually just the outer rim), you convert grey to colour by using the ball to draw an outline, the game filling the centre of your shape with colour for you. There's no clock, so you can essentially take your time.

Robots patrolling each level do provide a steady threat, however, wiping a life off should they come into contact with either you or your colourful trail mid-run. You can trap them, if you dare, by sealing them in a wall of colour. Though, getting that close to them can often end in tears.

From the off, BurnBall is the kind of game where only the incredibly prudent or incredibly reckless will survive. It's quite possible to transform the map square-by-square, waiting for the coast to be clear before you venture out into the grey to draw that line.

Following such a strategy, however, means resisting making that brave, brash dash that turns half the screen in one go.

The more you play, BurnBall is less and less inclined to let you rest on your laurels. Bugs appear later on that, unlike the robots, creep around both the gray zones and the relative safety of your coloured sanctuary, eating away at your share as they go.

Again, lives are lost on touch, with the consequence that you're essentially chased into the grey, making those mad bolts for glory compulsory rather than optional.

It's the kind of challenge that anyone who has tackled Dr Awesome or even Virus will be used to. Unlike those rival titles, BurnBall's blatant Sonic-spin just makes it feel tacky.

It arguably has the best controls of all the JezzBall clones out there, with just the slightest of tips sending the ball rolling. Yet, the game's trite take on Sega's superstar puts it at odds with the leagues of style icons making waves on the App Store.

It isn't a reason not to buy, but it does leave you thinking that its world would be just a little bit less gray if the setting that was a little wilder, a little bolder and, dare I say it, just a little bit more colourful.