When done well, tilt controls are brilliant.

They free up the screen, meaning you don't have to wave your chubby digits in front of all the action and fun that's happening on your phone. They get rid of the clutter and let you get straight to the heart of the gaming experience.

Which is exactly what the Xperia Play does with its slide-out controller. You'd think, then, that a combination of the two would make for a surefire hit. Sadly, that's not the case.

Mega roll

South Park Mega Millionaire is a tilt-controlled platform game that sees you guiding the four foul-mouthed stars of the hit cartoon through a variety of Japanese game show-themed levels. For some unexplained reasons Stan, Kyle, Kenny, and Cartman are wearing rollerskates.

You tilt your phone left to roll them left and right to roll them right. Pushing the X button, or tapping on the screen, will make them jump.

Each of the levels has different wacky obstacles for you to navigate, be they pools of peanut butter and acid or platforms made of slippery bacon. There's also a Wheel of Misfortune, which adds even more crazy trials to the next level you have to face.

Crude, rude, bad attitude

If you like South Park's base humour then you'll be right at home with Mega Millionaire. It's crude, lowbrow, and massively offensive if you take offence easily. It's also fun, with well designed levels and a smooth but challenging difficulty curve.

Where the game falls down is its Xperia Play optimisation. Or rather, its lack of it. With the controller slid out, tilting the Xperia feels unwieldy,and without the controller you may as well be playing on any other Android device.

South Park Mega Millionaire is fun, and what it does it does very well, but it's about as optimised for Xperia Play as its source material is subtle.