With the help of his magic camera, Dr. Robotnik/Eggman has captured Tails and Amy and locked them away as cards for some unknown and evil reason. Sonic, Shadow, Silver and Knuckles, once alerted to this kidnapping, head out to find them, and ultimately are forced to race against once another during their quest to stop Eggman's evil plan. Sonic Rivals basically takes the awesome 2 player Vs mode from the original Sonic 2 and wraps a game around it. What you have is several interestingly themed levels, each with 2 stages and a boss fight. As one of those 4 characters, you must race one of the other characters from the start of the stage to the end goal, as fast as possible. If you beat your rival then you beat the stage and move on to the next, simple as that. Along the way you collect rings in typical Sonic fashion, pick up power-ups, and launch an assortment of time delaying attacks against the opposing character. The concept is pretty straightforward and anyone familiar with Sonic or the series should be up and running in no time.

I wasn't expecting much out of Sonic Rivals in regarding to the gameplay, but most of what Backbone has put together works pretty well. Very much like your classic Sonic titles, you basically race towards the right of the screen in one general direction at full speed. What differentiates Rivals from other Sonic games, is that it dumps a good portion of the slower platforming segments in favor of a nearly start-to-finish high speed chase. There are a handful of sometimes difficult stages that require a few well-placed and timed jumps, although most are designed for speed, first and foremost. Surprisingly, many of the stages are fairly nicely constructed, varied and interesting. The boss stages in the game also work quite well, with you and your rival competing to see who can take Eggman down first. The stages are not the game's primary problem, however. All of the characters feel and play essentially the same, so the developer tossed in offensive and defensive power-ups such as fireballs, ice blocks, a tornado attack and star power to mix it up. The addition of these special attacks seem a little cheap and don't really fit in with the rest of the game or series. It's far too easy to lock-up your opponent or be frozen yourself, and many times it feels as if a clean efficient run through the stage comes secondary to launching off a long range attack or two. The stage obstacles, multiple paths and general layout do a good enough job on their own at skewing the results.

Graphically, Sonic Rivals is solid and sometimes borders on spectacular. The game plays entirely in classic 2D Sonic style, yet the characters, enemies, and stages themselves are 3D and constructed entirely of polygons. The characters are relatively simple and look good on the PSP's small screen, and the levels, which range from the typical Emerald Hill-type zone to outer-space, are definitely the graphical highlight of the game. It's really difficult to tell in screenshots, but most, if not all, of the stages are huge, very animated, and speeds along at a nice framerate. As it should be, Sonic Rivals is also a very fast moving game and the engine has no problem keeping up with the twists, turns and boosts.

Sonic Rivals has a decent soundtrack, actually, although it's also very forgettable. There are a few short voice clips here and there to go with the low-budget art and voice-bubble story scenes, and sound effects are classic Sonic through and through.

The actual single player experience is over rather quickly even when taking into account multiple characters and storylines. So to bump up the replay factor, Backbone tossed in a card collecting game to try and keep you hooked. As you play or replay/complete stages, you earn cards which are then used to unlock various in-game features such as additional character customization options. On top of the single player story and challenge modes, you can also connect via the PSP's wireless functionality and race against a friend in the game's multiplayer modes. Your collected cards can also be "put on the line" when playing against a friend, just to make things more interesting.

For the most part, Sonic Rivals pulls it together pretty well, but the game feels more like a mini-game than a fully fleshed out product. Overall, Sonic Rivals is unfortunately too short, and the concept is too simple, to hold the interest of most gamers for very long. The engine would definitely work really well in a proper 2.5D Sonic game... so hopefully we'll see something of the sort in the near future.