It's no longer enough to just talk about multiplayer and singleplayer. Games like Call of Duty: World at War, Resident Evil 5, Saints Row 2, and Dawn of War 2 mess everything up. They blur the line between multiplayer and single-player, between campaigns and challenges, between co-op and competitive. This screws up the review process. It's like going to see a double-feature and then having to write a single review of both movies. Videogames these days are large; they contain multitudes.

Halo 3: ODST is one such game. The campaign mode is disappointing. But the firefight mode is wonderful.

Read about firefight mode after the jump.

Firefight mode in Halo 3: ODST is the perfect Halo game. If there are two things Bungie does well, they are weapons with personality and aliens with personality. Firefight mode celebrates the intersection of these things, with all the fat of the Halo games trimmed away.

There are no long hallways and there is no torturous narrative. You don't have to escort anyone and you don't have to deal with your warthog gunner not being able to hit anything. There are no pre-placed snipers. There is no time limit. Master Chief himself is nowhere to be seen. You and up to three friends pick one of the eight maps and then hold out as long as you can while randomized waves of aliens assault you, gibbering and growling and hucking grenades and flanking you and dying obligingly to leave an assortment of guns scattered at your feet. It is Halo's Greatest Hits, The Condensed Version.

With each wave, the difficulty is boosted by "skulls", which are new rules that make the game more difficult and also increase your score. At pre-determined points, health packs and weapons are restocked. Every so often, you'll get a freebie bonus level in which you kill as many aliens as you can. Once you run out of lives, the game is over. At which point you can go back and admire the action or study it using Bungie's excellent theatre mode.

Firefight mode works just fine as a solo game (unlike, say, the Nazi zombie mode in Call of Duty: World at War). In fact, I've logged more hours just plugging away at a high score on the easy difficulty level by my lonesome than I've spent in the campaign mode. As with Bizarre Creations The Club, it's really gratifying to master firefight mode as a scoring system. But once you bring in more players, you can feasibly raise the difficulty level and enjoy wider tactical options. Not to mention you can blame your buddy for not covering you when you get killed.

There's splitscreen support for two players, but you can only play online with people from your friends list or your "recently played" list. This is an odd decision. Does Bungie assume all Halo fans are members of an online community? What's a guy to do who only has a couple of people on his friends list and none of them have ODST? As with Bungie's consistent refusal to add bots to their multiplayer game, it smacks of a "my way or the highway" attitude. There's a reason the Halo online community is so childish and hostile to new players. This sort of parochialism is part of the reason.

All of the eight maps are taken from the campaign. Two of them can be played with night lighting, which just means you have your night vision on the entire time. All but one of the maps is some flavor of city plaza, although some plazas are more open than others. The non-city map, Lost Platoon, is also the best. It's destined to be the Blood Gulch of firefight mode. Choppers circle an outdoor fortress. Tanks shell it. Waves of enemies assault the main stairway, come up the narrow side staircases, or occasionally jump the railings. You have to go downstairs to get the rocker launcher, which is in the room near where the warthog is parked. Lost Platoon is also the only map with vehicles, which gives it a wonderful Road Warrior feel. And unlike the other maps, the aliens come from all sides. You don't have the luxury of having you back against a wall.

So how does firefight mode measure up to other co-op shooters? The horde mode in Gears of War 2 is more tense and driven mostly by the cover system. Since Gears has no "trash" monsters like the grunts and jackals in Halo, it's missing the wonderful feel of being overrun by fifty creatures at a time. Gears 2 is a grim meeting engagement based on the endurance of giants pouring bullets into each other. Firefight mode is a colorful cartoony Alamo in comparison.

Resistance 2 knows how to bring on the crazy big swarms and keep you hooked with an RPG leveling system, but there's very little personality in the monsters. Furthermore, the division of labor among the three classes is so carefully calculated. Firefight mode is much more of a free-for-all that can play out any number of ways.

Firefight mode is far less chaotic and peripatetic than Left 4 Dead, and therefore it's more accessible. It doesn't constantly demand that you shootshootshoot and movemovemove. You get to hang back and wait for monsters to come through doorways. The emphasis on health as a limited resource is a big part of both Left 4 Dead and firefight mode. It's also worth pointing out that Valve and Bungie are neck-and-neck when it comes to personality, although Valve's personality extends beyond the bad guys. Both games also stand out for gameplay that rewards skilled players (i.e. people who are really good at twitchy shooters).

I'd say firefight is closest to Resident Evil 5's mercenaries mode, but not in terms of how they play. Instead, they both demand resource management when it comes to health and ammo. They're both wonderfully dynamic, unfolding differently every time you play them. There's even a bit of a puzzle aspect to how you approach the maps. They're playable solo, but they really come into their own with other players present.

But whereas Resident Evil 5 is an alternative to the traditional run-and-gun gameplay, Halo 3: ODST embraces it whole heartedly. Resident Evil 5's mercenaries mode is also built to play in short sessions where time management is crucial. There is no such limitation on firefight mode, which can easily last a couple of hours if you're good enough (or playing on easy).

Also, Resident Evil 5's multiplayer gameplay is something new and different. But there's something so deliciously traditional about firefight mode in Halo 3: ODST, because this is what Bungie does best. Not telling stories. But giving us toys to fight battles. Firefight mode is the playground Bungie has either relegated to its multiplayer community or diluted with earnest stuff about glassing Mombasa or Master Chief riding a bomb through space or Guilty Spark explaining alien artifacts. This is Halo. The pairing of a charging brute and a plasma pistol, or a shielded jackal and a sniper rifle, or a plasma grenade and ten gibbering grunts. This is the genius of Bungie, lean and muscular and a giddy delight.