Sonic Unleashed did a remarkable job of pissing people off. Despite reasonable sales, the Werehog gimmick ruined an otherwise competent platformer with unwanted and cumbersome combat; it literally tried to turn Sonic into something he's not. Unleashed wasn't completely devoid of enjoyment, though. The 2D sections offered some of the best platforming the series has seen in recent years, and fans were vocal about the fact they wanted more. Thankfully - and surprisingly, given their track record - Sonic Team were all ears. Sonic Colours makes a whole game out of the good bits in Sonic Unleashed - there are no Werehogs, talking swords or uninvited friends to spoil things.

Perhaps taking a cue from a certain Italian plumber, Sonic Colours is set in space. Consumed by guilt and remorse for his previous misdemeanours, Eggman has put his evil plans to one side to build an intergalactic amusement park; a place of balloons, rollercoaster's and trumpet playing Badniks. As the title alludes, it's a very colourful place. The map screen is effervescing with colour, with the entire spectrum of the rainbow covered in glowing neon and flashing lights. With the wrong frame of mind it could be considered brash or garish, but it's hard to complain in an age where most games are painted in a medley of browns and greys.

Suspecting an ulterior motive behind Eggman's foray into the entertainment and leisure industry, Sonic and Tails decide to check the place out. Their suspicions are quickly confirmed; the theme park is nothing more than an elaborate guise for another of Eggman's crazy plots to take over the world. It happens to be his most diabolical plan yet; to kidnap, kill and harvest the power of an endangered alien species. These aliens - Wisps as they're known - are not only central to the plot, but also the gameplay. By rescuing these Chao-like creatures from each level, they'll rather graciously lend Sonic their powers. With a quick shake of the Wii-mote (or tap of the R button, if you're playing with the classic controller) you can turn Sonic into a rocket or an airship, or something altogether more ferocious. The purple wisp, for example, transforms Sonic into a little purple shark of sorts, which chomps its way through anything in its path, growing in size as it does so.

Despite these new power-ups, Colours is a pure, gimmick-free Sonic game. In streamlining the experience, Colours achieves a much better sense of speed than previous games, putting the recent Sonic 4 to shame. Each level plays out on a combination of 2.5D and 3D planes, with the perspective flitting back and forth as Sonic bounds along. The controls are tight and simple, and even the camera is on its best behaviour throughout. All the criticisms levelled at previous 3D Sonic outings have been ironed out.

Each zone - or planetary system as it's represented in Colours - plays host to four or five Acts and a boss, meaning you'll spend far more time in each zone than you would in previous Sonic games. There's not a green hill, ice-capped mountain or other generic-platform-level in sight either, with thematic inspiration coming from far more interesting places.

Sweet Mountain is perhaps the best example of this, which sees Sonic zipping through a planet formed of cake and biscuit, swinging off lollipops and fending off enemies brandishing whisks. Structures made of burgers loom in the distance, and every now and again Sonic will do his trademark loop-de-loop around the rim of a doughnut. The level design is fantastic, with multiple paths based on which Wisps you choose to use, and inventive use of platforms and springs. There's no faffing about, fighting or solving puzzles, either, it's just a case of getting from A to B without dying.

Of course there are still things to collect. As well as the usual smattering of gold rings, Sonic Colours also introduces shiny new red ones, of which there are five dotted in precarious places around each level. Mario has clearly had quite an influence on Colours, but this can only be considered a good thing. With Mario Galaxy 2 setting a new benchmark for level design in platform games, it's encouraging to see SEGA upping its game too.

It is let down in places, though. With six zones you'd expect six unique bosses, but Colours features only four, the other two being slight variations. Considering how diverse and varied the rest of the game is, this is a rather strange decision. A lack of checkpoints is equally as frustrating, especially during difficult later levels; the game forces the repetition of huge great chunks of a level, which quickly leads to boredom and, on occasion, the throwing of control pads.

What surprised me most about Sonic Colours was how much I enjoyed the story side of the game. It's still as cheesy as you'd expect from Sonic, but a tongue in cheek tone makes it a far less annoying experience. "I know I say this every time," says Eggman after explaining his evil plot to his minions "but this time nothing will stop me!" This self referential humour in combination with Sonic's occasional disregard of the fourth wall does the game a lot of favours. This is also the first game to take advantage of the vocal talents of Roger Craig Smith, the same chap who voiced Ezio Auditore and Chris Redfield. The delivery of dialogue is therefore of a lot higher quality, and brings the standard of the story up as a whole.

Sonic Colours is a great return to form for Ol' Blue. Without the distractions of combat, hub worlds and pointless Wii-mote waggling, Sonic Team has been able to put all its efforts into creating a platformer Sonic fans can be proud of. The quality of the level design is what separates this from previous disappointments, and it's certainly better than that on show in Sonic 4. Despite a few niggling flaws, the only real complaint I have is not being able to play the game in high definition. Something to work on next, SEGA?