Let's be clear: the original Xbox - that big, black brick of a console - was not, by any stretch of the imagination, a success. If it hadn't been for a certain first-person shooter from an unassuming studio known for their not-quite Doom-killing work on the Mac, who's to say if Microsoft would have weathered the storm that met its clumsy entrance into the industry? But Halo: Combat Evolved saved the brand from utter embarrassment; it built the install base, outmanoeuvred the sceptical press and inspired the fans immeasurably. It was the single most significant reason to buy an Xbox, and it seemed a portentous sign, an unspoken promise of the great things that could come - if only the console had enough time to flourish.

Microsoft was canny enough to know that it had lucked out, but its hunger to recapture the inestimable success of Bungie's console debut left the mighty corporation short-sighted. It rushed out an ambitious but unpolished sequel that disheartened many involved and knocked the fledgling fan community for six by dropping the Xbox outright in favour of its impending successor. Jumping the queue was a bullish move that could have stopped the building momentum of the platform in its tracks - even now it's uncertain how much good the decision did Microsoft in the long-term. The Xbox 360 sold out at launch around the world - of course it did - but early adopters found there was precious little fun to be had with their fanciful new consoles. Precious little lead-time meant that the launch games were uniformly unimpressive and third-party pickings were slim for much too long. More to the point: while a next-gen Halo was as good as assured, no-one expected it to arrive for years. Bungie, quite simply, weren't ready to save Microsoft again, and for a long moment, it looked like the 360 could suffer the same unfortunate fate as the dodo and the Dreamcast.

Then Geometry Wars: Retro Evolved happened. It's impossible to know just how significant Bizarre Creations' first Live Arcade game was to the eventual success of the 360 and its subscription-based online offering, but to say that it was anything less than crucial is to undersell its importance. A twin-stick shooter at once instantly accessible and incredibly deep, Retro Evolved was a showcase piece that helped justify a great many early-adopter expenses. It was an instant classic that brought the very best arcade games to mind: addictive and frenetic, simple but challenging, Retro Evolved proved to be, like the Halo franchise before it, all the validation that gamers needed to buy into the next generation of hardware. It was, as much as any single game can be, a perfect bite-sized experience - not, you might think, the ideal candidate for a sequel. But it sold, and a lot.

Three years on, Bizarre Creations' modest masterpiece has returned to XBLA, and in its absence, the little game that arguably saved the 360 has seen several intermediary iterations. Hidden away in Project Gotham Racing 4, Geometry Wars: Waves was a short, sharp shock that spun the familiar mechanics of Retro Evolved into a brief but thrilling new kind of experience. Meanwhile, Geometry Wars: Galaxies for the Wii and DS took the titular mode of Retro Evolved and wrapped it around a lengthy campaign of isolated encounters, as well as introducing geoms, little crystals dropped by defeated enemies that bumped up your all-important multiplier. Geometry Wars: Retro Evolved 2, in its turn, incorporates these new mechanics seamlessly, demonstrating with absolute assurance that there's life left in the old arcade game yet. But at twice the price of Retro Evolved, the first question this sequel has to face down is that of value for money. Its six modes - versus the original's two - make for an easy answer, an ideal back-of-the-box brag (if only there were a box to brag on the back of), but what truly sets Retro Evolved 2 apart is the distinctness of those modes. Almost without exception, the new ways to play are each as complex and interesting as the original Evolved mode, which itself makes a welcome return.

It'll take maybe a half-hour for players to unlock all six of the modes and it's a surprise, initially, to see that Evolved isn't the starter course of this lavish spread; the only mode available when you first start the game is Deadline. A familiar experience, Deadline is basically Evolved as we know and love it but with infinite lives and a definite endpoint at the three-minute mark -yet those simple differentials subtly change the way the game plays. The only real penalty for losing a ship is your momentum, so a collision or two aren't going to devastate you in the way that losing a life in the first three minutes of Retro Evolved would. And if you're shooting for the leaderboards, you'll want to focus on rounding up geoms to build your multiplier as quickly as possible. Deadline is pick-up-and-play familiar but distinct enough to draw you into the crucial differences between Retro Evolved 2 and its predecessor; a great mode to start with, in all.

Spend enough time with Deadline and you'll unlock King, an unapologetically King of the Hill-influenced mode of play where you cannot shoot unless your ship is parked in one of several rings around the arena, which is all well and good except these safe zones begin to phase out the second you arrive within them and while the enemies are largely unthreatening to begin with, the longer you last, the more of them spawn. It doesn't take long for King to devolve into that characteristic mess of colours and shapes that the Geometry Wars franchise is known for, but what sets this mode apart is that it's not so much about wiping out every enemy so much as surviving the onslaught long enough clear a path from one ring to the next.

King is one of the more strategic modes of Retro Evolved 2, and - alongside Pacifism - it makes for a great change of pace between the bursts of more traditional twin-stick shooter fare offered by Deadline, Waves, and the returning Evolved mode. This isn't to say that those modes of play aren't worthwhile but rather that the quieter intermissions make such balls-to-the-wall action all the more effective when it comes. Despite their consistent strength, however, the best of the new modes is one of the more thoughtful alternatives. By taking away your ability to shoot, as in King, Pacifism turns the core mechanic of traditional Geometry Wars gameplay on its head. You can still destroy the constant stream of enemies but it takes more than just pointing the right stick in their general direction; Pacifism brilliantly subverts the usual cat and mouse routine by casting players as not the hunter, but the hunted. You'll have to dodge and weave around the mass of enemies that quickly build up, playing on single-minded AI foes that follow you doggedly until you can lead them to a gate. Zip through the gates while avoiding the deadly edges to trigger a pleasing explosion that take out all the unrelenting blue enemies in close proximity; chain gates together and the explosive area widens. You won't last long - in the end it's almost survival horror - but you can amass a truly impressive score relatively quickly and there's nothing in Retro Evolved 2 quite so satisfying as the pop of a perfectly-timed gate traversal and the resulting flood of geoms.

Evolved mode, meanwhile, does exactly what it says on the tin. Three lives, three bombs and a myriad of enemies make it the deepest, most flexible mode of play, but - perhaps as a reaction to the die-hards bored by the calm before the storm in the original Retro Evolved - the difficulty ramps up perhaps a little too quickly, meaning that most players will see precious little of what the latter stages have to offer. Nevertheless, Evolved will hold your attention long after the brief but brutal formations of Waves mode - harvested almost wholesale from its origins in Project Gotham Racing - have humiliated you for the last time. All the same, it's great to see Waves available without the racing-game entry barrier and, to top it all off, there's Sequence, the final unlockable mode, where the tried-and-true Geometry Wars formula is separated into a series of intense thirty-second slices that are by the halfway point almost impossible to survive.

When all is said and done, Retro Evolved 2 offers quite the package. It's probably the best value you'll get for your money this year on XBLA and the chances are you'll be playing long past that point, honing your skills in an endless effort to dominate the leaderboards that the developers have brilliantly incorporated into the mode select screen. Bizarre Creations plainly understand that without robust online functionality - a disappointing omission, if an understandable one - the best way to extend the lifespan of their game is through competition. If you're connected to Xbox Live while playing then the high-scores in the corner of the screen aren't even your own, but those of your more skilled friends. Expect some pleasant abuse when you beat someone's Pacifism record and count on gloating voice messages when a compatriot takes yours down. Like Burnout Paradise's seamless Freeburn multiplayer, it's the ideal integration of a brilliant system that we can only hope other developers work into their own efforts.

Visually and aurally, Retro Evolved 2 is a significant step up from the original. It runs in full HD and the extra resolution is well spent on sharper ships and still-more extravagant particle effects that distort the arena nearly beyond recognition. At times it can be a little difficult to see everything that's going on, but when the going gets tough, Bizarre has built in unique sound cues to clue you in on the particulars. The soundtrack, too, is excellent, a clever concoction of pulse-pounding anthem and electronic ambience whose only real failing is that you'll have to be hella good to hear it all. Retro Evolved 2 more than matches up to the original - go back to it after a few rounds and you'll find the graphics muddy and the audio lacking by comparison.

In fact, in just about every respect, Bizarre has done a bang-up job of making Geometry Wars relevant again. Geometry Wars: Retro Evolved 2 looks, sounds and plays better than such a simple shooter should, by all rights; it's breathless, frenetic and addictive in all the right ways - and definitely not for the faint of heart. If the Xbox 360 is in any danger of flagging then Bizarre, at least, have got Microsoft's back, because what they're created in Retro Evolved 2 is singularly the best game on XBLA to date. Evidently, there's potential left to wring out of the old twin-stick shooter yet.

Reviewed by Niall Rough for AceGamez (All Rights Reserved).