There are also additions. Skill Games are unlockable mini-games that separate elements of the main campaign levels, twist them into fun little high-score challenges, and give them their own leaderboards. There's a task where you have to drag a shallow trailer full of bombs as far as you can go across bumpy terrain without causing an explosion. There's another where you have to build up speed and then bail just in time to propel your rider down deepening steps piled with glass, logs and other damaging furniture, the goal being to break as many bones as possible. There are a couple involving the number of flips you can do and the height you can reach in what are effectively pinball machines, complete with flippers. And there are a couple involving my friends the big metal spheres. None is the new Monkey Target of console mini-games, but each has its own charm, there are 16 in total, and if your friends play Trials then you see on-screen indicators for their distances, times and other feats.
There is also an impressively detailed level editor, which allows you to construct your own courses out of all the objects you find in the main game, and then share the levels, albeit only with people on your friends list. We haven't been able to test the sharing element pre-release, but I've built a few things, like a giant wooden penis, obviously. The process was laborious, because making levels is laborious, but it felt like the path of least resistance, and it's surprisingly easy to make something that takes a good bit of effort to overcome, either by applying the lessons of the main game or through innocent quirks of whatever picture you're inevitably trying to draw with the level furniture.
Even without the Skill Games and the level editor, though, Trials HD would still be a roaring success, and it comes back to the tremendous variety in the main campaign. One level may be a lightning sprint over a series of high jumps, where the idea is to thread speeds and ideal landings together to keep up the pace, but the next may deepen the troughs, and introduce high-wire girders that allow you to make forward progress at greater speed providing you can execute the right jumps. The next may go helter-skelter, with a series of loops, or physics tricks, like drawbridges you need to strike to knock them down, but also maintain enough friction to cling to lest you fall backwards to your doom. Having wrung exquisite lighting out of its manly game engine, RedLynx sometimes goes bonkers for fireworks too, most memorably in a level called Unfair Bombardment, where everything is a potential explosion.
Discipline is the key to success, but it's smoothly enabled by the instant restarts and admirable design. Overcoming key challenges - like the contradiction between the need to put the back wheel down to maintain friction on sharp inclines, and the competing need to hold yourself over the handlebars to avoid falling backwards - is an urgent necessity, and would be even without the friends leaderboards and all the rest.
But the fact is Trials HD does have all the rest. It may cost a hearty 1200 Microsoft Points (£10.20 / 14.40), but even playing it from start to end will take hours, and it's a game built for endless replay and community expansion beyond that. It may not have some of the PC features, like ghosts and multiple camera angles, but neither change intrudes on the experience. It may be on a gamepad, which is slightly less exact than the three-fingers-on-the-directional-buttons of the PC version, but Trials pros will be able to emulate the majority of their feats within a few hours of practice. And it seems to me those are the only slight issues. Otherwise it's wonderfully designed, justifies the price, and may end up being the best thing on Xbox Live Arcade all year. If you're in any doubt, there's even a trial version. Thud.
9 / 10