Halo 3: ODST stands as the red-headed stepchild of the Halo franchise, and let’s be honest, that’s not totally undeserved. It’s the short one. The side-story. The one where you don’t play as a Spartan super-solder. It’s got a screwy narrative structure and the previous game’s multiplayer, itself exiled to an extra disc like a cheap afterthought. Everything about ODST feels like a mere warm-up for a real Halo game (specifically, 2010’s Halo: Reach).

On that last point, at least, ODST gets a bad rap. A bunch of heavy Halo-hitters populated its development team...in fact, the same people trusted to home-run Halo: Chronicles, developer Bungie’s episodic series collaboration with film director Peter Jackson. When Chronicles fell through (alongside Jackson’s Halo feature film), the team's creative director, Joe Staten, proposed ODST to keep his people off the unemployment line. They finished it in 18 months.

Personally, I didn’t care for the game much when it first released in 2009, and I hadn’t thrown it on since. But now, three years later, with Reach in the rearview mirror and Halo 4 just a few months out, I decided to see how the stepchild had aged. Better than I would’ve thought, as it turned out. And a little worse.

For starters, the whole feel of ODST takes some getting used to. You play as Orbital Drop Shock Troopers, the Airborne Rangers of the Haloverse -- highly trained specialists, but fully human...and vulnerable. A shockwave scatters the squad all over the enemy-occupied city of New Mombasa during a Rookie's first combat drop, and you spend significant chunks of the game alone, moving through the deserted city streets hunting down clues to the fate of your team.

It's Bungie's first open-world environment, and it shows. Minus encounters with Covenant patrols and frequent rooftop snipers, New Mombasa displays all the personality of skim milk, and I'd classify traversing it mainly as a chore.

I'd also call it broken. Unless you save your game very carefully indeed, you'll lose progress at a staggering rate. It's entirely possible to quit a game and find you'll have to replay an entire level just to catch up to your stopping place. Replay a different mission, and the game might just forget some or all of your progress with the easy press of a button.

Really, New Mombasa serves as a hub for levels that fill in the story's blanks, re-casting you as each ODST in turn, and I'd forgotten how fun those missions are. They come in fairly bite-sized pieces with a good bit of variety -- even the three vehicle-based scenarios bare zero resemblance to each other. The game generally doesn't present a huge challenge (I made it through the entire first half of my replay without dying), but exceptions to that rule come across as very, very effective. When two massive, heavily armored Hunters come running out, you don't have the same confidence you might carry while playing as the Master Chief. Squad leader Gunnery Sergeant Edward Buck, facing a pair of unstoppable killing machines without any backup, lets a little desperation sneak into his voice.

I like that. You're not in control of a robot here, but real people who feel hardships and the elation of victory far more than any Spartan. And from a pure geek perspective, it's tough to beat the voice-actor trifecta of Nathan Fillion, Alan Tudyk, and Adam Baldwin...three principals in Joss Whedon's cult sci-fi series, Firefly.

And I'd love to have Fillion shouting "Yeah, that just happened!" as a message notification on my iPhone.

ODST recycles a lot of assets (thanks, in no small part, to its abbreviated production schedule) with only a few new weapons: a silenced pistol and modified, silenced submachine gun. I originally dismissed that SMG as the "ditch-me-now gun." This time, I dialed into its charms a bit better. As a scoped-in, mid-range gun, it can really tear an alien religious fanatic to shreds. Anyway, I’m a sucker for sound-suppressed weaponry with scopes, and I found myself wishing Halo hadn’t dropped it from existence post-OSDT.

Which is funny, because some people would cheerfully drop ODST in total from existence. I used to be one of those guys, but not so much anymore. In fact, I'd call ODST a vital component to Halo as a whole...and maybe even an important point of reference for the franchise moving forward.

No lie, I got severely frustrated with my progress vanishing (particularly since you've got to backtrack across the entire city to replay old missions and unlock the final level), but the story and the characters carry a stronger emotional core than most of the Master Chief's adventures. He's the invincible icon. These guys are underdogs, fighting their tiny corner of the war. You get to know them better and sympathize with their plight. You feel for them more. It's an element Bungie picked up to great effect in Reach (created in parallel to ODST), and I have to suspect it's one reason Halo 4 will feature a much-publicized emotional journey for the previously emotionless Chief.

So while ODST still comes across as an anomoly, long-term, it'll be seen as an important step.

The events depicted aren't particularly consequential. New toys don't show up much. It's buggy as all hell. But as a small story about the heroes who never see their name in lights, Halo 3: ODST successfully gives us a different perspective on the Covenant War with smart, short level design and compelling characters. The frustrations, which are many, go hand-in-hand with its positive qualities, which are also many. The flaws feel deeper and the successes greater now than they did three years ago.

Halo 3: ODST is absolutely its own beast, but despite the quirks, it's as vital a piece of the saga as any other entry in the franchise. That's definitely not something I would've said back in 2009.