I guess the problem is that while your changes have cumulative benefits and alter the overall look of your quad-bike, the vehicles don't have the familiarity or iconic style of the cars in a Gran Turismo or Forza, and putting in a new engine or changing the brakes doesn't have the same glamour it does when you're hot-rodding a Mustang or a humble Honda S2000 in those games. The garage feature also benefits from and loses out to an easy one-click option which instantly produces an optimised racing or freestyle setup, and while you can spend ages creating and upgrading different bikes for different events, after a while the thrill goes and you start using the automated option.
The bigger issue, however, is that when it comes down to it the single player mode just isn't all that expansive. After a while the new tracks dribble through rather than flood in and you find yourself racing the Italian or NZ tracks for the umpteenth time, still having fun, but feeling slightly let down. Pure's central game mechanics are so tight and the courses so enthralling that you could never have a dull time playing it, but you can't help wishing that this was a game of Burnout: Revenge rather than Burnout 1 proportions.
Of course, there's a hugely enjoyable online multiplayer option to make up for this, with smooth simultaneous sixteen-player action, not to mention a dedicated online only game mode where you can compete over particular feats of daring. All the same, I've come to the conclusion that this is the beginning of something great rather than its full realisation. No problem. That is more than enough to be getting on with, and more than enough to make Pure one of the easiest and happiest recommendations I've made this year. Really, you don't have to think too hard about it; just buy it, play it and have a great time.
Pure isn't the biggest or deepest off-road racer out there, but you'd have to look hard to find one that puts out a better time. Black Rock Studios has created a great crowd pleaser and, hopefully, just the start of something great.