When did you lose your faith in Halo? Maybe you haven’t, or maybe you never had it in the first place. Maybe it was as far back as the tedious early sections of Halo 2, or the less interesting passages of Halo 3. Or maybe it was last year’s Halo: ODST that did it, with its short campaign and dated visuals. Well, whenever and however you lost your faith in Halo, Reach is good enough - actually great enough - to remind you why the series wowed us in the first place. If this is to be Bungie’s last game in the series, then it’s a fitting capstone, and one of the best sci-fi FPS games ever made.

Unless you’ve been hiding under a rock for the last few months, you probably know the basics already. Reach is a prequel to the original Halo: Combat Evolved, depicting the fates of a squad of Spartan troopers - Noble Team - during a brutal Covenant attack on the frontier planet of the title. As the game progresses, Noble Team gets involved in attempts to recon and repel the invaders, then in the last ditch efforts to save what can be saved and grab some small scrap of hope from a desolate situation. To say more would be to spoil things; one of Reach’s pleasures is how cleverly and surprisingly it brings the Halo saga back to its very beginnings.

We mean that in more ways than one. The more Halo has gone on, the more the series has pulled away from some of the factors - the epic battles, the scenery, the wide-open spaces, the way each set-piece accepts a range of different approaches - that made it seem so revolutionary back in 2001. With Reach, the series has rediscovered its mojo, but also found a new sense of scale that makes each big moment that much bigger than anything we’ve had before.

Helped by an all-new graphics engine that drags Halo up to the standards of Gears of War and Modern Warfare, Reach is a dazzling experience for much of its running time, bringing back the sense of wonder you might have felt during classic Halo levels like "The Silent Cartographer", and taking Bungie’s vision of sci-fi warfare to a whole new level. Yet, at the same time, there’s a grit and detail to Reach that anchors it in a more tangible, human universe. If ODST was successful in one thing, it was in making Halo a more personal story, with interesting characters you could easily relate to. While its portrait of Noble Team isn’t always so successful, Reach definitely benefits from the same thing.

Part of the game’s success comes down to the fact that you no longer feel like a superhuman warrior surrounded by losers. As Noble 6 - a newcomer to Noble Team at the start of the game - you’re initially made to feel a junior member of the Spartan gang, and throughout the game you’ll get solid backup from your fellow Spartans, plus various marines and ODST troops. Despite this, the minute-by-minute play is classic Halo. Move fast, pick your targets, adapt your tactics, and keep scavenging for weapons, as you’ll be running out of ammo on a regular basis.

You still benefit from one of the most interesting and varied armouries in video games - with a handful of interesting new additions - and you’ll be fighting some of the finest enemies. Once again, there’s a sense that Bungie has gone back and rediscovered what made the grunts, jackals, hunters and elites work in the first place, with the elites in particular seeming more cunning and aggressive than they’ve been in ages. Across the board, AI is absolutely top notch, and another thing you grow to appreciate is how unpredictable this makes the game. Die and restart at a checkpoint, and you’ll rarely - if ever - have the same experience of the same section twice.

On top of this, Reach throws in a couple of new twists, including some excellent aerial sections and a fantastic burst of space combat. It’s typical of a game that moves fast to keep you entertained, with few - if any - levels that outstay their welcome, and some of the most exciting assault and defence set-pieces of the series. New tools, like the jetpack that went down so well in the Reach multiplayer beta, are introduced and handled brilliantly, adding new tactical options without ever making you feel like you’re unbeatable. And best of all there’s no - let’s repeat that - no Flood. For the first time in a Halo game it’s all killer, no filler, the whole way through.

Criticisms? The big story moments aren’t always as big and moving as they’re clearly meant to be, and while the scale of the battles - sometimes with dozens of combatants on each side - is impressive, it’s frustrating to get killed by a fluke grenade just because you turned the wrong corner at the wrong time. Hunters are, perhaps, a tad overused, and there are also some oddities with checkpoints, where you’ll jet over or accidentally run past the checkpoint area, die, and find yourself further back than you really should be. None of these are deal-breakers. In fact, you usually don’t mind having to repeat a section for the simple reason that there’s always some new tactic or trick you could have used.

Nor should we forget the other reason Halo made its reputation: multiplayer. Reach brings us the most comprehensive and advanced set of modes and options yet, with new team-based styles like the Enemy Territory-esque Objective and the superb, cooperative Firefight mode, that give those of us who don’t live, breathe and sleep Halo a chance of getting something out of the online game. Throw in the persistent identity, with new bits of armour you can unlock in both the online and campaign game, not to mention the video capture features and level-mangling Forge mode, and it’s clear that Halo is back on level pegging with Modern Warfare and Bad Company 2 in the online gaming stakes. In fact, it might be one peg beyond.