From time to time we get sent discs with preview code from various developers or publishers that features an upcoming release, and regrettably the experience of playing it is not always as exciting as it's made out to be.

Typically, it's in a distressed state of construction with various pieces missing. It's almost always prone to crashing, there are entire segments that are out of place and it's a safe bet to assume nothing is entirely the way you'll see it in the final game. Along with any form of refinement, an explanation as to which particular aspects require more work is almost always missing as well, which gives you a sort of "game within a game" experience as you mentally dissect every glitch and try to determine if it's something that will get fixed, or something that will be released as an "exciting new feature". And then you have to comment publicly on which is which.

Case in point - MotorStorm Pacific Rift arrived the other day, and as we'd played some earlier preview code at Sony's head office a while back we thought it'd be a relatively simple affair to see the difference between the builds and come to some kind of conclusion about how the final release would look. After all, developers don't just sit around for six months drinking coffee and thinking of ways to delay their titles until closer to Christmas, do they?

First though, for those who haven't played through the original MotorStorm, you're missing out. It's hardly a unique concept, but high-speed racing on variable, collapsible terrain with a bit of vehicular combat thrown in is inevitably a recipe for success. It's a slightly simpler cousin to Flatout 2 that happens to be exclusive to Sony's next-gen console, something Sony decided to nurture by snapping up developers Evolution Studios shortly after the game was released. A solid, fun racing title that has not only shipped more than three million units to date, MotorStorm has earned its own fair share of praise from industry pundits and consumers alike.

MotorStorm Pacific Rift has been widely slated to pick up where the original left off, and is set to offer sixteen tracks instead of its predecessor's eight along with a new vehicle class (the Monster Truck) and a bunch of graphical and tactical racing tweaks. There's no reason to suspect it's going to be anything but a success. This isn't a major overwrite of the existing franchise, think of it more as a tune-up, a polish and a new set of wiper blades.

Unfortunately the preview code we were supplied didn't really reflect the potential of this game. The single-player race mode certainly felt less refined than the multiplayer code we'd played a few months back. Granted, the large banner proclaiming that the code was "80% complete" along with numerous caveats detailing how foolish it would be for anyone to assume the final game bares any resemblance to what was being presented could hardly be missed, so we'll have to assume the last tweaks will go towards improving texture detail, and a number of slight handling modifications that will hopefully balance out a lack of low-speed manoeuvrability.

Of the three vehicles available in the preview code, the motorbike felt the most agile, and despite having less protection from the elements we had no problem setting rapid lap times. The new class, the Monster Truck, suffered from the aforementioned low-speed handling issues that caused a few headaches on the narrow paths, likewise the mid-sized truck would frequently get bound up on scenery that wasn't always easy to spot.

We'll take the advice of the developers on this one and assume it's a work in progress. After all, once we actually got a bit of speed up around the "Cascade Falls" track, it was easy to forget about low-speed annoyances and instead concentrate on retaining the upper hand over the AI competitors.

"Cascade Falls" (the only single-player track provided in the preview build) is set on a tropical island which obviously provides us with a look at the Pacific focus for this sequel. We've been promised a lush tropical setting with what's been described as "interactive vegetation", and to be fair that's exactly what you get. Not only can you race along dirt tracks next to giant rock outcroppings on an island that looks remarkably like the one featured in Lost, you can fly under waterfalls and skim across rivers, or cut through forest paths and take advantage of the non-linear world provided to you.

You can also hurl your controller clear across the room after hitting the same virtually invisible pebble on the side of the track that causes your vehicle to flip every single damn time you take a particular corner... but again, this was preview code and those sorts of details will no doubt be resolved by launch day. (Touch wood.)

It looks as if the same controversial AI weighting has been retained for Pacific Rift as well. Despite finishing several races in pretty much the same time, our placings varied wildly from the front of the pack to the rear due to the rubber-band algorithm gifted to your competitors. It didn't appear quite as obvious as the first, although we'll wait until the final release before commenting much further on this aspect.

The elements of verticality included with Pacific Rift will either enthral or confuse. This isn't a racing simulator, so if you think jumping between peaks at the helm of a truck - with wheels the size of the mess Winston Peters is in - seems a tad on the unrealistic side, you might want to pick up a copy of Gran Turismo 5 Prologue instead.

There's also another title - Pure - coming up that's set to offer the same crazy aspects of high-speed racing, such as vertical drops, stunts and a healthy dose of insulting your competitors, so it will be interesting to see how the new kid manages against this already-established franchise.

In the meantime, we'll be waiting eagerly for a review copy of MotorStorm Pacific Rift - this is one title that could be extremely popular this festive season, so stay tuned for more soon.