When I found out I'd be reviewing Sonic Rivals I immediately paid the nearest available gypsy to sharpen my favourite knives in readiness for a critical slashing not seen since Tom's review of the terrible Xbox 360 Sonic game. Initially, my fears seemed well founded too, as the opening level is way too hard and seems brutally unfair. Yet, once I started to progress through the stages, the strangest thing happened, I began to really enjoy myself. In fact, I was so engrossed I took to carrying my PSP around with me to squeeze in a quick level whenever I could, in an addictive fashion that a pre-rehab Kate Moss would have approved of.

Once you get used to the format, Sonic Rivals is a pure adrenaline blast of a platformer that's damn near impossible to put down without the intervention of a group of supportive friends. I failed one level no less than 10 times, but after every beating I just dusted myself down and went straight back to work, with precious little of my usual bleating about "ramped up difficulty levels". While it does take some questionable liberties with the classic Sonic template, this game is nevertheless one of best pick-up-and-play games to appear on the PSP to date and is another great showcase of why the console is still a major contender in the handheld wars.

The sinister Dr Eggman has created a special camera that he uses to turn Amy and Tails into cards before pegging it away from an understandably miffed Sonic. Now it's up to the blue hedgehog, or one of the four other playable characters (each with their own storyline), to get in hot pursuit of the villain and rescue his pals. There are six worlds in total to race through and an average of two levels and a boss fight in each one, which might not seem a lot, but some of these stages have a steep learning curve and mastering the nuances of each course is the key to victory (although a little luck and some quick reactions can occasionally see you sail through in one go).

While it's essentially a 2D platformer, Sonic Rivals uses 3D to add extra depth to the backgrounds and obstacles, and the camera angle frequently shifts to highlight particularly action packed moments, like zooming down corkscrews or swinging on giant boulders. Fans of earlier Sonic outings will feel right at home with the controls and will soon be nostalgically performing spin attacks just like they did back in the old days, before Shadow and the like came along to tarnish the good hedgehog's name.

Until the closing stages, when timed challenges are the order of the day, most of Sonic Rivals pits players in a head-to-head race to the end of the level with an AI rival like Knuckles, Silver and, yes, Shadow (somebody put that hedgehog into hibernation already). Unless you're terminally useless, most of the time you will be pretty much neck and neck with the competition and relying on the good old homing spin attack to try and get an edge. Handily, power-ups - including mines to lay as traps and ice cubes to freeze rivals - can be picked up during the level and deployed at choice moments. Each character has their own signature move as well, such as Tails' Hammer Punch, that prove pretty useful in the heat of the battle.

Most of the levels are mad scrambles all the way to the end and it's the relentless, heart pounding pace of the game that is its most endearing feature. There are multiple paths to follow in each stage, all depending on how quickly you respond to button pressing icons that pop up at obstacles, so the levels offer plenty of variety and replayability too by encouraging you to hunt for the perfect route and shave seconds off your best time. The only time the action ever slows is when the occasional platform challenge pops up. Here the breakneck speed switches to an agonising crawl, while you bounce around with only the unreliable analogue nub for support. These sections can be distracting and frustrating if you get stuck, but they should keep the hardcore platforming contingent happy.

The visuals are colourful and look great on the PSP

What really impresses about the main game is the fantastic presentation. The graphics are sharp and clear, with no sign of blurring, and the backgrounds are superbly detailed (the fairground stage is a real highlight). Sonic and his pals may all be pretty small sprites on the screen, but they are still distinctive and bursting with character. Heck, even the rocky soundtrack is pretty exciting and adds to the blistering pace of the experience.

Outside of the main storyline, there is plenty more to enjoy in Sonic Rivals, such as Cup Circuit races that mix up stages from throughout the game and customisable direct challenges against other rivals. Friends can also race in the ad hoc wireless mode, leading to some pretty tense encounters as you jostle for first place. For every race you win in the game, you will collect an art card (like Sonic box art from the '90s) and these can all be viewed in a gallery. It's also possible to unlock new costumes for the characters, if you're into that sort of thing.

Outside of the odd frustrating stage, the only criticism I have of Sonic Rivals is its brevity. The main story is very short and you are unlikely to want to complete it with all the different characters unless you are a diehard fan. Still, while nothing groundbreaking or revolutionary, this is a very polished and thoroughly enjoyable game that proves, along with last year's Sonic Rush on DS, that Sonic is far more suited to handheld consoles than he is their bigger brothers.