This review concerns Halo 3's single-player and co-op campaign component. For a full review of its multiplayer mode, check out our Halo 3 multiplayer review.

To play Halo 3's campaign as a single-player experience, the game lives up to what one would expect from its title; it is very much "the third Halo." The core Halo gameplay is here as strong as ever--sometimes stronger--and everything that fans love about the series almost seems to have been magnified or reprised, but it also is very much a sequel. It does feel as if this is what you might have played if Halo 2 had kept going, and while some of the series' rough edges have been smoothed out, traces of them remain.

Really, this is hardly a negative point overall. The unique gameplay elements that make Halo as a series great are still relatively uncommon, so slotting them into new environments and situations is welcome. The thrill of cresting a hill or entering a large, cover-heavy arena to find a horde of Covenant aliens, and the knowledge that the battle could play out any number of ways--but you're going to do it this way--remains as tangible as ever.

The series' large and diverse selection of weapons, which is a big part of what creates that combat diversity, returns, bolstered by a few new additions. Successively headshotting a row of grenade-chucking grunts with a battle rifle, charging and rifle-butting the brute they were accompanying, stealing the downed foe's brute shot grenade launcher and using it to fire a shot into an explosive barrel adjacent to a cluster of enemies surrounding a turret, then hopping in the nearby dormant Ghost hovercraft to deal with a menacing Wraith tank is one of those heart-pumping experiences that is difficult to find elsewhere.

Most existing fans are likely to initially find the new weapons on the whole less versatile than their time-tested compatriots--though new additions such as the Gravity Hammer, which hilariously sends foes soaring through the air upon impact--but as usual the game's single- and multiplayer components dovetail nicely, and I ended up finding more single-player uses for some of the less crucial armaments simply by being forced to use them in multiplayer maps with limited weapon selection.

Most notably, Halo 3 ditches Halo 2's emphasis on dual wielding and returns to center stage the wonderful gun-and-grenade gameplay theme that the series does better than any other game. There are far more viable one-handed weapon configurations throughout the game than in Halo 2, and for the most part dual wielding becomes something you can do if you're into the whole John Woo thing but never something you need in order to be effective.

Unfortunately, many of the series' continual hangups remain. For both good and ill, playing Halo 3 in single-player feels as though Halo 2 did not end in a bizarrely abrupt cliffhanger but rather instructed you to insert Disc 2 into an Xbox 360 console. Of course, with a series that has such a massive and devoted following, it would have been risky to mess with the formula too much, and Bungie has certainly included plenty of value and freshness beyond the standard single-player--more on that later--but in the core campaign very much plays it safe.

Visually, Halo 3 has a clean, distinctively "Halo" look, although it does not feel as though it has been hugely overhauled for Xbox 360. The game is overall of a higher graphical fidelity, and running in high definition is always nice, but it likely won't be used as a system showcase. NPCs are improved over their Halo 2 chopped-up counterparts, but they still have an odd rough, clay look. Will you care when you're knee-deep in Brutes, Warthogs, and grenades? Not really.

In any case, most of Halo 3's visual impressiveness comes not from texture work or shaders but from the impressive sense of scale; its huge outdoor battles, which few shooters still do particularly well, continue to impress. And, as series aficionados know, its vehicular gameplay remains essentially the best in any shooter--the feeling of smashing a Warthog through ranks of enemies while a gunner mows them down remains practically unparalleled, as does stealing an enemy's Ghost and turning it on him.

There are also a few moments of genuine visual inspiration, including one scene nearly at the game's beginning. For the most part, the game simply looks like more Halo, but in the occasional instances when environments break out of well-explored ground, they show that Bungie's artists clearly have plenty of ideas left to be mined, and more than anything else suggest that the company's next non-Halo project could look radically different.

The sound design, unsurprisingly, maintained its extremely high standard--Halo 3 is one of those games in which reloading is in itself a small joy, with each weapon sounding far more convincing and unique than you'd think fictional weaponry would, and the Battle Rifle is undoubtedly one of gaming's most satisfying firearms, in large part due to its great tactile and auditory presentation.

Marty O'Donnell's score has some of its best moments in the series in Halo 3, particularly when O'Donnell scales down the instrumentation and resists the urge to increase the size of the orchestra or stray into cheesy overdriven guitar overlays--the new piano interpretation of the Halo theme is arguably the most striking rendition of it yet--but I was disappointed to find that overall there is less variety and musical exploration to the soundtrack here than in the last game, with most of the tracks being rehashes or fairly standard series fare.

I have little to say about Halo 3's storytelling, which is peppered with more of the not-nearly-as-clever-as-they-think-they-are musings that took center stage in Halo 2. The plot, which veers between boilerplate sci-fi and generally ineffective emotion, is still largely ignored during gameplay, then given in large, static doses between levels. This is probably for the best, as those who love Halo's established style of plot delivery will get more of what they have already enjoyed, while those who find it less exciting can easily move onto more game. One thing that should please just about everybody is that this game ties things up much better than did Halo 2; there is a bit of a sequel setup, but not one that will leave you scratching your head for three years.

The amount of Master Chief worship in the single-player game--reflected in Microsoft's current ad campaign, which to be honest is more emotionally affecting than anything in the game itself--borders at times on the comical, propelling the Chief into the levels of in-game virtual hero worship occupied by figures such as Half-Life's Gordon Freeman.

What is more frustrating is the continued appearance of backtracking, a series level design issue that established itself in the first Halo. At one point I imagined that it always came down to limited development time, but at this point I think it is simply an ingrained part of Bungie's design sense. Thankfully, there are fewer instances of levels simply being reversed and replayed than before, and they tend to come in smaller chunks, but one can't help but be slightly baffled that this annoying gripe remains.

Continue reading for some of the more frustrating parts of Halo 3--as well as the best.

The part of Halo 3 with which I most take issue is a sudden shift later in the game to gameplay that feels like it should be played as a run-and-gun shooter whose level design does not really lend itself to the open Halo-style tactical combat--but playing it as a run-and-gun, particularly at higher difficulty levels, seems nearly impossible even after playing through the rest of the game on those same diffculty levels.

Combined with the fact that one of these levels consists of the most significant example of backtracking in the whole game, and an irritating (and unskippable!) storytelling mechanic that constantly interrupts gameplay to deliver vague attempted profundities, it really feels like a too-hard push for unneeded gameplay variety. Halo is at its best when it gives players the widest range of possibilities to take on a given battle, and these later sections feel as though the designers slightly lost the plot, both in the literal and figurative senses.

Still, Halo 3's positive points outweigh its negatives by a huge margin; I myself have already played through the game no less than three times--and just because the campaign is not particularly surprising as a whole does not mean it contains no surprises; there are some genuinely unexpected and grin-inducing moments--sure to be universally loved is a recurring Shadow of the Colossus-esque "boss" battle that, despite being repeated numerous times over the course of the game, is tackled in so many different and continually fun ways that you always find yourself looking forward to the next one.

What makes Halo 3's campaign truly different from its forbears is in its almost stupefying level of playability. For those who enjoy Halo, the games have always been replayable simply by virtue of their very dynamic combat gameplay, but Halo 3 truly raises the bar here, not just for Halo but for replayability of single-player and cooperative FPS gaming as a whole--and, to be honest, it is unlikely anyone will catch up any time soon.

First and foremost is the new four-player co-op, which can be played over Xbox Live--praise be! Cooperative gameplay improves any game, and four-player co-op is all the better. Few words even need be said about this feature; surely you can imagine how enjoyable it is. Though it is fairly straightforwardly implemented--this is no Army of Two, nor should it be--the game does the obvious things it should, such as provide extra vehicles when needed. The Live implementation was an absolute must this time around, and here it is. It's great. Only one player gets to be a Spartan; the rest play as allied Covenant Elites--college dormitories the world over will no doubt by punctuated by cries of, "I call Master Chief!" for months to come.

What adds even more value to both the single-player and co-op is the also-new scoring system. During the campaign, you can enable point scores for yourself in single-player, or for individual players or the team in co-op. This adds a new competitive layer to the campaign that most games never address. Achievements are awarded for a "par" score on each level, and co-op games can now have an explicit competitive element allowing for more detailed bragging rights than ever--after completing a level, you'll get a multiplayer-style score drilldown that shows in depth how each player performed. You'll know who kicked ass, and who dragged things down. Inspired!

As if that were not enough to add campaign value, the hidden skull system first seen in Halo 2 is back, and much more polished this time around. Bungie designers admit that Halo 2's skulls, which were hidden in obscure parts of the single-player levels and enabled challenging modifiers to the game, were a bit of a last-minute addition. Not so in Halo 3, where they get their own submenu. Finding a skull in a nigh-unreachable ledge or hidden room in the campaign unlocks that skull in a campaign options screen, and enabling it adds a new trait to the campaign--perhaps enemies are upgraded, or dying takes you back to the very beginning of the level.

The more of these skulls you enable, the higher a multiplier you get on your campaign score, giving a genuine incentive to find and use them. It also adds a new level of difficulty scalability to co-op. Perhaps you and your three friends steamroll through Legendary mode--you probably won't when you start piling up the skulls.

Then there's the much-vaunted film recording. Yes, PC gamers grumble at the hype for this feature, noting that it has been available on their platform for over a decade. True enough, but rarely has it been implemented as cleanly and easily as Bungie has done in Halo 3. Every game you play, in single-player or multiplayer, is recorded as gameplay data, and you can choose to save it permanently to your hard drive.

When you play a video back, you can detach the camera and fly around wherever you like, even exposing the artifice behind the level design and enemy spawns, as well as creating new on-the-fly cinematic shots of your explodey exploits. You can trim these videos down and upload them to Bungie's servers, then recommend them to your friends, or you can simply invite your friends into a lobby and all view the video together, pausing just as a grenade detonates and tears a Brute to bits.

All in all, for such a mainstream series, Halo 3 feels surprisingly tailored for the hardcore player. The least interesting part of the game is its basic single-player campaign, which at first sounds like a damning complaint--but the reality is that there are so many ways to experience that campaign, and its best battles are simply so much fun to play again and again, that the package still feels like a great value. Despite its flaws, the Halo series' fundamental gameplay has always been top-notch and this game is no exception.

The hordes of Halo fans who simply want more Master Chief will be satisfied by a continuation of the series' established gameplay, while the hardcore players who are looking for more will find that the four-player co-op, skulls and scoring, graded difficulty system, and films will provide them with far more replayability than any campaign has any right to.

And that's without even touching the true multiplayer side.

(Check back later today for Shacknews' review of Halo 3's multiplayer component.)