Polyphony Digital knows cars. The development studio's four remarkably successful Gran Turismo racing games have proven that beyond any doubt. Now, with the release of Tourist Trophy--their first racing title focused on two-wheeled transportation--it seems they know motorcycles too. Better said: Polyphony Digital knows how to make good racing games, period.

In it, there are more than 100 shiny, branded motorbikes, each with its own distinct engine sound, plus loads of logo-plastered gear to be earned so you can customize the look of your rider. Non-enthusiast might not know better, but it sure smacks of authenticity all the way through. Not that it really matters; everything looks and sounds swell, and that should be good enough for the people who play the game for it let's-play-dress-up functionality, but at the end of the day, all of which you'll spend riding a viscously steep learning curve (with maybe a small break as you take a trip to the electronics store to buy a new controller after smashing your last one in frustration), Tourist Trophy is flat out fun; the riding physics of it all, fantastic.

Through a sophisticated combination of audio, visual, and physical game outputs, Tourist Trophy provides a sense of speed, inertia, and wheel traction (or lack thereof) few other racing games can match.

It's easy on the eyes, too (on a 42" Hewlett-Packard plasma HDTV in widescreen format at 1080i, anyway), with the bikes and tracks--many of which are recognizable carry-overs from Gran Turismo, like the classic Laguna Seca circuit--looking outstanding, each and all. The game treats you to crisp lighting reflections, beautiful rider animations, and intricately detailed courses, be they countryside or cityscapes.

The career mode is unashamedly modeled after the Gran Turismo franchise, where players must take biking tests that teach a variety of motorcycle techniques for braking, cornering, and throttling up and down in order to earn the licenses that let you compete in each successively difficult race. There's a garage in which you store and tweak your collection of bikes, as well as a gear screen that allows you to work with an ever-expanding collection of helmets, jackets, gloves, pants, and boots.

Unlike Gran Turismo, however, where players earn cash to spend on cars and upgrades, Tourist Trophy players earn bikes directly by entering and winning specific races. And there's a catch: the races can be extremely tough.

The whole game is pretty hard, actually, and even GT veterans who typically breeze through the early competitions may find themselves losing and repeating races in Tourist Trophy right from the beginning. More likely than not, non-motorbike enthusiast simply won't have an understanding of the subtleties associated with motorcycle racing and the game makes no apologies for that. Going off track just once (or, worse, spilling) will destroy your chances of winning most races, and that has gameplay riding if not crossing the fine line between challenging and frustrating on several occasions.

There's also a noticeable lack of any online functionality. There is a split screen multiplayer option, but it just feels dated--and has a detrimental impact on graphics to boot. In this day and age, online modes are a staple, a total given in a racing game, regardless of the kind of vehicles involved, except conspicuously lacking here.

In the end, Tourist Trophy won't find the kind of success enjoyed by the Gran Turismo series. Despite the fact that it's a fine racing title, many mainstream gamers will be turned off by the whole motorbike thing, while those mainstreamers that dare to try it will find it difficult enough to suddenly recall why they don't like the whole motorbike thing in the first place. Bit of a shame, that, because it's actually a deep, challenging, value-packed experience, as any racing game enthusiast will attest.

• TIP (read: nitpick): Tourist Trophy is a glutton for memory. It takes up about 1.5MB on a standard 8MB PS2 memory card (or nearly 20% of the total space). Though this is more a problem with PS2 hardware itself rather than the game. But if you're sick and tired of excitedly booting up a game for the first time only to realize that you don't have enough space to create a save file, thus forcing you to reset your console, enter the PS2's poorly designed media browser, and delete hours of hard work you've put into other games--which you will never play again now that the save files have been erased, then fork over a few more dollars and get another memory card for this one. Better still, hound Sony about bringing on the PS3 with its promised hard drive. Ask them to eat the nickel and dime gleaned from sub-industry of overpriced memory cards. Remind them that the world was ready for a console with a hard drive for some five years, when it starting buying Xbox. Yeah, the one with a hard drive. Thanks for catching up.