Bizarre Creations must love a challenge. Following up the hugely successful launch title Project Gotham Racing 3, which is still being played over Live regularly now, is no mean feat. The series has always based it's gameplay on the principle of winning races as stylishly as possible, with the reward coming in the form of Kudos points. This attracted a hardcore following, with some mastering PGR3's combination scoring system to a point that far exceeded the expectations of even the developers themselves. So what can gamers expect from the latest addition to the arcade racing series? Let's start with the big changes.

Firstly, most obvious new feature for this installment to the series is the addition of motorcycles. Many were dubious when the game was first previewed due to the fact that bikes didn't allow such massive drifting as the supercars of PGR3, and thought it may unbalance races with their superior acceleration. Happily, this isn't the case. With a much broader range of vehicles on offer this time, including some modern classics like the Sierra Cosworth, much effort has been made to keep races balanced. The new career layout comes into play here, with class restrictions forcing a choice of vehicles that although may have superior attributes of their own, overall present an even field on the track. Yes, bikes do accelerate extremely quickly off the line, but their top speed isn't that great and cornering requires much more finesse, with late braking riders paying the price.

The inclusion of motorcycles are a welcome addition to the game.

Of course, riding your vehicle doesn't provide you with protection from other racers. Often times, being toppled from your bike by a car power sliding through your careful driving line can cost you the race. Ultimately, it all balances out. Kudos on bikes are scored by taking fast lines through corners, but also by performing stunts. Using the B button allows you to perform numerous tricks whilst pounding down the straightaway, including popping a wheelie and dismounting, then standing on the seat on one leg. There are more basic taunts as well, including waving back at the racer you just overtook. That's sure to frustrate opponents into ramming you into a wall in Live races. Because your rider is visible, you can customize your leathers and helmet, which adds a little individuality when you take the race online.

The Kudos system itself has also received an overhaul, with the manner in which points are scored changing. Instead of the limitless combos some racers could achieve, Kudos are now earned in stars. Each star represents 100 Kudos points, with 1 to 5 stars being awarded for each individual move, or chain of moves. For example, sliding through Las Vegas' winding sections without hitting a wall or regaining traction will earn you a maximum 5 stars. More Kudos can be tallied on top of this, but no more stars can be earned in one combo. The reasons for earning Kudos have changed too, with vehicles, tracks, new game modes, and even ultra high priced gamer pictures all unlockable at the PGR Shop. Finishing in first place will win you the race regardless of Kudos most of the time, but all those bonus points you accumulated from power sliding your way through each city can now be spent at your leisure.

Changes to the career mode go hand in hand with the changes to Kudos scoring and alter the way you'll play through the game. Gone are the unreasonably high expectations of flawless laps, shaving hundredths of a second off and still falling just short, or the complete frustration of having to try ridiculously hard cone challenges over and over again. PGR4 proudly sports an all new Race Season, featuring a calendar of events and ranking leaderboard that sees you tasked with climbing from 72nd up to the number 1 spot. On each calendar week, several events are available depending on your rank. Initially, you'll only have the option of entering Amateur ranked races, which see you in F class vehicles. This allows you to get the hang of racing again, which is good, as drifting feels slightly more challenging this time around. Winning individual events or championships earns you ranking points, which help you climb the leaderboard and unlock more. Throughout the season, there are also Invitationals, where invites are dependent on your performances over the season. These races don't offer ranking points as rewards, but rather give the chance to unlock exclusive cars and bikes, or wild cards which allow you to enter championships above your rank.

What this all means is if you don't meet the target time on a cone challenge, for example, you'll simply finish in a lower position, cry about it, then get on with the season. For those perfectionists who love to correct themselves, don't worry, you can try that event again in the next season if you want. Because you'll be ranked higher by then, you could potentially replay each new season completely differently, entering only professional championships for example. Also, each season offers three Majors. These are challenging events that work on a tournament basis, and you compete against drivers that may be far above your class. Often you will have to qualify by completing a Hot Lap within a set time. Rewards are big in these events, with the winner taking a significantly greater amount of ranking points away than you'd earn from normal championships. Arcade Mode is also available, which is more like PGR3's traditional challenges. There are plenty of groups of events available, each with the added challenge of completing them with 2 and 4 wheels. Like before, each can be attempted on Silver, Gold or Platinum with a win earning you the relevant medal.

The next big evolution from PGR3's sunny race days is the inclusion of some dramatic weather effects. Rain, snow, fog and even thunder and lightning will grace you with their presence as you accelerate through the career, each effecting the on-road physics you've become accustomed to. Racing in snow, for example, will give a very different feel to a Ferrari Enzo as you try to power slide out of a 90 degree corner. Fog affects your judgment severely and depending on its density, it won't help your vision either. All of this is done in stunning graphical style, as you'd expect from the series. Rain is especially noteworthy, with the in-car view really doing justice to the way the wipers flick back the droplets as they smear across the windshield. Water also pools in dips on the track, a real accomplishment for the game's physics, which can cause your vehicle to hydroplane if you lock the brakes up whilst passing through puddles.

Online play is a huge part of the PGR franchise, and this hasn't been forgotten. You can play with numerous ranked and player match options, with team-based racing being the newest added feature. This allows a party of racers to earn points that count toward an overall team score. Once again, it's all laid out with a functional lobby, allowing changes to the match settings and tracks at the press of a button. With ranked matches using the TrueSkill ranking system, you'll be matched against drivers of similar skill as you take on your first online championship. Here, the same principles as career mode are applied, except now, there are with living, breathing opponents. Hours will simply disappear during racing online championships, and the online component is among one of the best parts of the game.

PGR3 was well known for its attention to detail, and PGR4 is no different. Four entirely new cities have made their way into the game, each as detailed as ever. All the previous game's locations are included, as well as Shanghai, St. Petersburg, Macau and the incredibly challenging Quebec. Each city is recreated in full, with routes plotted through actual roads. This gives PGR4 a genuinely realistic depth that you won't find in any other racer out there. Looking at the scenery as you race is addictive but deadly, as tiny details can be picked out but ultimately distract you from the race at hand. If it exists in reality, the chances are it's in the game.

PGR4 has some of the best racing visuals on the 360.

This is where the Photo mode comes in, allowing you to pause at any time whilst racing and take a snapshot in free camera mode. If you happen to catch a great action shot, you can upload it to the all-new PGR On Demand service where it can be viewed and voted on by the world via Xbox Live. The same goes for video clips and even full saved replays. This really expands on the Gotham TV mode featured in PGR3 and adds a host of community features. A few tweaks in the photo editor can produce photo realistic images that are quite honestly jaw-dropping. Just using the free cam to look at every tiny detail on the cars is impressive enough without even taking in the surroundings.

With all this beauty around you, PGR also has one of the most diverse soundtracks available in any game. With the exception of the slightly overused menu music, which can get irritating after a short while, there are a variety of in-game tracks on offer. Artists range from Lupe Fiasco, a popular Hip Hop producer, to Beethoven and Tchaikovsky. If you haven't tried racing a Ducati 999R Xerox super bike at hair-raising speeds through St. Petersburg, while one of the classical masters rings out in your helmet, you really haven't lived. Also, engine noise has been given an overhaul and each car now has the authentic sound you'd expect. A Ferrari at top speed now sounds like a giant angry wasp passing you at lightning speed, just as it should, whereas the giant Hemi powered muscle cars have the deep growls and grunts you'd expect.

So for all of this good, is PGR4 a better game? It hasn't changed too much, but it has expanded on what made its predecessor so successful. This is arguably one of the best and most involving racers ever built, and its immense attention to detail will constantly take you by surprise. The new career layout is a vast improvement from PGR3's millisecond shaving nature, and the addition of bikes has really spiced things up. Not only is this one of the best looking racing games out there, but it is one of the best games out there. As arcade racers go, this comes hugely recommended, and is a game no racing fan can do without. Apparently the idea mill is already churning for PGR5, but topping this game is going to be Bizarre's greatest challenge yet.