As we reflect on the success of digital games like Fez and Bastion, which point the way to a brave new future without discs and boxes, it's easy to forget that the idea behind Xbox Live Arcade was originally rooted in the past. It came from the days of upright cabinets like Ms Pac-Man - games that were best played alone, but with friends, who would compete to displace each other's initials at the top of a rudimentary leaderboard.
It's no coincidence that one of the very best Xbox Live Arcade games, Trials HD, had this concept at its core. It was you and your 2D stunt bike against the track - a lonely battle to extract as much grip, balance and momentum from cruel arrangements of wooden ramps, oil barrels and tractor tyres as your mastery of the economical controls would permit. But really, it was you against the guy above you on the leaderboard.
The game's masterstroke, however, was allowing you to review how the guy above you on the leaderboard came to reside there. By downloading replay data you could examine his route through the course you had just completed and, thanks to an on-screen recreation of control pad buttons, even observe how he was moving his fingers. There were no secrets between the best players and those chasing them. Every breakthrough went viral.
There was, however, a knack to graduating from the lower ranks to the chasing pack, and for some players the barrier to entry was literally too high. It's one thing to leap from ramp to ramp, using the addictive instant-reset button to retreat to the last checkpoint every time you fall over backwards, but it's another to climb over a six-foot wall on a motorbike with little or no instruction, no matter how many replays you watch.
It didn't help that Trials HD was one of the gloomiest games on Xbox Live. With no room to manoeuvre, no idea how to climb the wall in front of you, and only the murky surroundings of an abandoned sawmill or rundown factory to keep you company, it was easy to lose patience. Cut off from the brain trust at the top of the leaderboard, you were no longer alone but with friends - you were just alone.
If that was how you felt, then Trials Evolution is very much made to win you over. The flat 2D gameplay remains, but the tracks are now bright and spacious, and your path through each of them winds through hill and vale, across collapsing bridges and dams, over the curtain walls and battlements of crumbling castles, through labs and building sites, and across hanging islands in the deep blue sky. The surrounding detail is far more lively, too, whether it's cars tipping off a cliff, a spiked mace swinging past your rear mudguard or giant stone fingers closing into a fist around the rock you just vacated.
Evolution is a much better teacher, too, beginning with a longer sequence of fast and accessible obstacle courses to catch your attention, heavy on high speeds and even higher jumps, before introducing you to more advanced skills through periodic licence tests. The whole game is more steadily rewarding as a result of these changes, and even when you do get stuck toiling against a difficult sequence of ramps, you're kept company by gushing rapids, rolling hills, gorgeous sunsets and soothing horizons.
"Trials Evolution keeps the likes of you - and me - satisfied despite its obvious concessions to less advanced players."
If 'accessibility' sounds like a dirty word in your manor, you needn't fear either, because Trials Evolution's biggest achievement is keeping the likes of you - and me - satisfied despite its obvious concessions to less advanced players. The very first course is a good example. It's a simple sequence of grassy hills that will have newcomers laughing into their shattered helmets as they launch themselves around, twiddling the left stick to get used to shifting their rider's weight in his seat. For the rest of us, it's a challenging, uneven sequence of inclines where every jump must be measured to conserve momentum on the next descent.
Initially there are three medals to earn on each course, and once you've unlocked 135 and claimed the Trials Trophy you open up a series of Extreme stages, along with Platinum challenges for each of the preceding events. At Extreme level, Evolution much better resembles the Trials we've come to expect, where every new checkpoint seems impossible to reach until you somehow claw your way there, and the faultless performances required to achieve Platinum times only find your fingertips after you've studied replays and scraped every last trace of grip, balance and momentum from the ground beneath you.
Withholding the Platinum goals for so long feels a little harsh on people who need no introduction to Trials riding, but any sense of disappointment is quickly forgotten as you set yourself to the task of unlocking them. As you settle into advanced competition with friends, you'll also appreciate the way other riders are now represented by a moving dot on-screen rather than a ticker at the top of the image.
Despite the quantity and variety of events, there are a few missteps. Sometimes the environmental details interrupt your progress too eagerly, like a series of water geysers that propel you upward a little too randomly for a game of such precision. Other throwaway ideas, like a level dedicated to Playdead's wonderful adventure game Limbo, are more successful, but these gimmicks often feel like Trials Evolution at its least assured.
The range of Skill Games is also a mixed selection. Some, like a task where you have to see how far you can ride juggling a large steel ball in a curved brace on top of your bike, or another where you need to fling your limp ragdoll body between trapeze bars, are funny and memorable. But most are easily forgotten. There is something nice to be said for their inclusion, however, given that most developers these days would probably carve them out and sell them separately. (Obviously I'll feel silly if they show up on iTunes next week.)
The new multiplayer side of the game is much more successful. It's still you against the track, but this time there are up to three other riders in adjacent lanes. It's motocross, in other words, married to Trials' peerless handling; you're still fighting for grip, balance and momentum, only this time you have to avoid becoming distracted by the guy doing the same thing in the lane next to you. Alone, but with friends.
The inclusion of an enormously detailed track editor - the same tool developer RedLynx used to make the levels you're paying for - means that talented amateurs will be able to drag more life out of the game than you initially get for your 1200 Microsoft Points. But in truth, Trials Evolution is already fantastic value for money. It offers simple, one-player gameplay that uses leaderboards to provoke excitement and competition among strangers, and in this sense it has a lot in common with the original Xbox Live Arcade games. The way that it makes its challenging content accessible to a majority of players, however, is what singles it out as one of the best.