So what is the lure of this addictive title? Violence? Graphic depictions of gore? Realistic 3-D worlds? Nope - LocoRoco's success relies on three simple things: a revolutionary control system using the left and right shoulder buttons, a brightly coloured 2-D environment and a bunch of singing blobs.

The world of LocoRoco was a happy place, filled with happy singing LocoRocos of numerous different colours, but then the spiky Moja Corps arrived, determined to conquer their peaceful planet. But the planet is having none of it and, over the forty massive levels, gently shepherds the LocoRocos to safety.

Of all the features in the game, it is the concept of controlling the environment, not the LocoRocos, which makes it such a revolutionary title. Pressing the L and R shoulder buttons rotates the landscape by degrees and pressing both buttons at the same time will nudge your LocoRoco in the air, allowing them to ascend landmarks or eat those hard-to-reach flowers.

On their own, the multi-coloured creatures bounce around but are ultimately defenseless, but they do have some unique little abilities up their sleeves. The LocoRoco can grow bigger by ingesting flowers (although they're also quite partial to bugs and fruit as well), which can be found in the open or nudged into bloom. A jolt of lightening (invoked by pressing the circle button) causes the expanded LocoRoco to split itself into many smaller parts, allowing access to tunnels or fall through gaps and the internal workings of a stomach. Split up, the LocoRoco also form an impromptu choir, their acapella singing activates hidden sections of the levels, allows access to bonus areas chock full of flowers and bugs. Each level gives you the opportunity to rescue nineteen LocoRoco but sideline in collecting as much fruit and bugs as possible, the amount you find boosts the final end-of-level score and makes each level doubly challenging.

The levels are perilously filled with the Moja Corps, small black creatures with dreadlocks that like nothing more than snacking on the LocoRoco - these are to be avoided at all costs as once they eat one of your Loco's, you cannot get them back. Their minions are also present in the form of black spikes which will kill one rescued LocoRoco, causing its tiny shrivelled form to roll away but, if you're fast, the hapless creature can be reabsorbed and all is well once again. The Moja Corps are no great obstacle to dispense with, as long as jumps are well timed and the LocoRoco lands on their head.

The environments are shockingly bright yet also very simple in terms of design; it could easily be mistaken as a game designed for children but this is part of LocoRoco's innate charm. Each of the five worlds is colour coded with its LocoRoco inhabitants, who have their own unique look and singing voice. However, if, like me, you've fallen in love with a particular type of LocoRoco (such as the orange variety found the first world) you can always switch between them; entering a new world merely unlocks a new variety to play with.

Although the game takes place on the LocoRoco planet, each of the five 'worlds' is actually a different location within that planet. The terrain includes lush yellow pastures filled with fruit and flowers, an icy wasteland where LocoRoco slip and slide from A to B. After they are accidentally swallowed, the LocoRoco have to navigate the innards of a giant beast and there's even a humid green jungle. Each world is distinct in terms of colour and musical accompanyment but also has its own challenges.

Despite the look of the game, it's clear Sony have put a lot of effort into this. A good example of this is, whatever your LocoRoco's are doing, their tiny mouths are synched with the background music, especially during the vocal levels. Each level is vast with numerous paths available, but it can get a little frustrating when you can't find those last few blue bugs or elusive MuiMui, caretakers of the planet and keepers of sections of the Loco House.

As if the game wasn't enough, the UMD is also packed with bonus features including both demos released via the internet which can be beamed to other PSPs, the ability to take pictures in-game and then create your own photo album. The LocoRoco house lets you place items found in on your travels to create a unique environment for the rescued LocoRoco to live in. There's also a bunch of really addictive mini-games which only makes the replay value skyrocket. This one game could keep you occupied for weeks on end.

LocoRoco is a weird game: a simple idea that has become a worldwide success. It's one of those rare titles that dissolves the boundaries of gaming and appeals to everyone from the kids to hardened gamers to grandparents! While it is not 'the' perfect game, it does come pretty close; the visuals appeal and if, by some chance, they don't then the perky toe-tapping soundtrack is certain to make everyone smile.