The team's emphasis on that all-important "X" is the key difference between Shift 2 and its competitors. As Tudor sees it, Slightly Mad's title is a racing game, not a driving game, and while it's a subtle difference in language it manifests in an obvious manner in the way the game looks, sounds and feels.
"The feeling you may have had screaming down the motorway or hurtling down a particularly nice country road in a stock or factory car are very different to competitively and aggressively attacking a racing circuit in an upgraded or race-spec vehicle," Tudor explains.
"The sounds are all different, the acceleration is much more intense, the weight of the car is lighter but the grip is better, the consequences for pushing too hard are dire, and there's a focused mental state you need to be in whilst your body is being punished by continual movement and adrenaline.
"This is the experience when you actually go and do it yourself in race-spec vehicles - which the team does at multiple points during the development process. Simply playing other games or watching it on TV is not an option here as they will both give you false readings."
Feedback from real race drivers was also important too. The Need for Speed franchise is currently being overseen by DICE head Patrick Soderlund, a massive real-life racing fan, Team NFS member in GT3 and winner of the Dubai 24-hour race. Another Team NFS member, Edward Sandström, was also involved in track days with Slightly Mad, and this level of professional assistance aided in embellishing and refining the outputs of the raw mathematical simulation.
"It doesn't stop at cars, either. Again, that idea of an 'X' helps here when it came to the feature of 'track degradation' and how the circuit gets chewed up over the course of a race. On TV, an incidental detail like the chunks of tyre rubber thrown up by cars hardly ever show up (even in HD!)," reveals Tudor.
"But the feedback from the drivers was that those things are extremely prominent - and significant - to a driver since they have the potential to lose your grip on that portion of the track. When drafting an opponent in front too, they often bounce off the hood and hit the windscreen with a particular sound causing a distraction."
This attention to detail not only helped to add new visual elements to Shift 2 but also allowed the developers to include new gameplay opportunities too.
"This kind of feedback is invaluable, since it gave our track artists a deeper sense of how prominent the black tyre marbles should be against the gray tarmac compared to in-car and TV footage also being used as reference," says Tudor.
"It also gave a neat gameplay bonus too - now there was a risk/reward mechanism for drafting an opponent. Sure, you'll get a minor speed advantage but there's also the potential to be caught in a wake of his tyres kicking up both gravel and tire rubber meaning a distraction as they hit the windscreen and a potential momentary loss of grip."
Convincing AI is also a key ingredient in the mix, especially in light of the continuing controversies surrounding this important element in just about any racing game you care to mention. With the original Shift, Slightly Mad boiled down the AI requirements to aspects such as overtaking, drafting, taking the inside line and getting a good start off the grid, which in turn distilled down to two particular driver types: precise and aggressive. Real-life parallels, as Andy Tudor points out, are along the lines of Schumacher vs. Villeneuve or Gronholm vs. Blomqvist.
"Profiles were created using traits that not only defined their raw 'ability' but their personalities too. So things like 'Risk Taking', 'Concentration', 'Grudges', 'Antagonism' and 'Adrenalin' were all present," Tudor explains.
"We then made around 15 unique profiles that dialled up certain attributes - so there'd be an AI who was really clinical and avoided all crashes but then there'd be another who'd actively bash into you, one that would swerve out of your way if you drafted him, and others that made silly mistakes when cornering etc."
By mixing in those different profiles into a single race in the original Shift, the studio hoped to capture the excitement of racing and an element of unpredictability, but the feedback from the community threw up some less welcome interpretations.
"We were given another perspective on the AI: players were having a great time racing only to be knocked off the track on the last lap by an aggressive driver and lose. Or they'd be driving side-by-side with the AI and they'd be trading paint with them in an effort to knock them off the racing line. Or they'd be approaching a corner and the car in front would spin out for no apparent reason," Tudor continues.
"In many cases, either an overly-aggressive opponent was ruining your race or they were appearing to do 'silly' things. Because there were a wide range of personalities in each race, these incidents were limited to a small percentage of the AI pack and instead of players identifying some as aggressive and some as precise, most were 'correct' and the rest were 'bugs' or 'idiots'."
While Slightly Mad retained much of the original approach to the core AI, a number of changes were made to reduce the amount of "bugs" and "idiocy" that occurred in the race.
"Our aim was to remove the 'idiots' with a three-pronged attack," Tudor shares.
"We streamlined the number of traits that created their personalities in order to reduce the randomness effect, dialled down or even removed the traits that caused either bizarre or harmful on-track manoeuvres, and focused more on their 'abilities' (defence, blocking, intelligence, passing, reactions) to achieve consistency and calibre within our AI.
"When you couple this with some matchmaking filtering to ensure 'aggressive' human opponents don't ruin the online experience, we think the pack racing experience in Shift 2 Unleashed is a lot of fun and so far, the reaction has been overwhelmingly positive to the changes."
It's clear that we haven't seen the end of the Shift series, and Slightly Mad Studios continues to work on concepts that may end up in a prospective sequel. Andy Tudor and his team-mates have a clear philosophy about how they want to proceed.
"I think the key to developing a successful franchise is community and innovation. With each iteration you have to keep the great stuff and enhance it, cut the stuff that didn't work or no-one is playing, fix or balance the existing stuff that's been nagging you, and then add a whole bunch of new stuff that your players are crying out for or has never been seen before," he says.
"Get it in early and playtest/polish it until release, then support the community after release and include them in discussions moving forward. If you're only ever adapting existing ideas then you'll constantly be playing catch-up, and players will simply see version 2.0 of a feature they've seen before."