The part of a Halo 2 level that was shown at E3 in 2003 morphed into what eventually became two levels, Outskirts and Metropolis, roughly divided into Old and New Mombassa, respectively, the city being divided into two parts by a river and connected by a bridge. While the trailer took place in New Mombassa with the player landing in a Pelican with Sarge to assist some marines, in the shipping game that Pelican crashes after being attacked by a Scarab, and you must make your way through the narrow streets of Old Mombassa and across a beachhead before reaching a Scorpion tank and heading out over the bridge to New Mombassa.
As with the cutscene that ends Cairo Station, we see parts of the game we've seen before, but in a different context, and sometimes this is quite jarring-- perhaps even more so than the changes between the E3 2000 demo and what eventually became the Halo and Silent Cartographer levels, in part because the changes are not as sweeping, but essential.
This level introduces you to your new favorite pain in the ass, too-- shieldless Jackals and Drones armed with Beam Rifles, the Covenant equivalent of the sniper rifle. At Heroic or Legendary difficulty, these units will spot you from afar and most likely kill you with one or two well-placed shots before you can react; until you know where to look for those units it's difficult to counter them, and you'll only discover that through trial and error. At Legendary, even knowing where they are doesn't always help unless you can find just the right spot where their shots hit some obstruction but you can still draw a bead on them. Thankfully, there are places like that in the level-- but again, finding them is an exercise in trial and error.
The gameplay can start to feel repetetive quite soon, as groups of Elites, Grunts and Jackals will pour out of nearby buildings and side passages, or jump from the rooftops in waves, much as groups rolled out of boarding ships on Cairo Station. Just when you think it's safe to advance past an area, you'll move on only to be attacked from the rear. Many parts of Halo 2 seem to be designed to modify the player's behavior, to make them more cautious and to handle more encounters from a distance. This was possible in Halo 1, but usually not required and often less challenging. There were parts of the first game, especially the marine-rescuing scenarios in the second level, where the use of the Warthog's LAAG gun, the sniper rifle, and the pistol allowed you to take out nearly all the Covenant units without putting yourself in danger at all; and, failing that, you could usually opt to just run them all down in the 'hog, even on Legendary.
No more. Getting vehicle kills is generally more challenging, and the addition of units that can snipe back means that you're not safe just because you keep your distance. Add in the possibility of being sniped by distant units while you're trying to fight close-quarters combat and you'll probably find yourself crawling through parts of Outskirts and being far more methodical about your progress.
Things start to open up a bit towards the end of the level and you get access to some vehicles. There's a large circular area which is probably the only place in the entire game that marines should be allowed to drive, because it allows them to circle endlessly, firing on a succession of targets. Just about everywhere else, marine drivers get hung up on crates, walls, other vehicles, or just about any possible obstruction on a level, and seem utterly unable to cope with it. As such, you're forced either to simply use the Warthog as a means of transportation, settling for the Marines doing the gunning, or as a stationary gun. Of course, now that Marines can drive, they're likely to come and steal your ride if you leave it unnattended, or come along and move the Warthog that you carefully placed to gun from a protected position. And if they don't, the Covenant might.
The Phantoms in this level are also a much bigger pain than dropships ever were in Halo 1; they return repeatedly to the same area to drop off reinforcements, as they did in the Halo level from the first game; but their guns are more powerful and they have three of them instead of just one-- another change that makes the idea of using Warthogs as stationary guns inadvisable at best.
The best moment of this entire level comes from-- as so many times during the game-- the music. After you exit from the back of the Zanzibar Hotel onto the beach and head across the sand towards the break in the underground highway tunnel, there's a marvelous little string and percussion piece called Ghosts of Reach. It creates a perfect mix of melancholy and militarism-- which feels especially appropriate at the Legendary difficulty level, since it's quite likely that if the Phantom and the reinforcements it dropped didn't take out your Marine buddies, then the Ghosts that attack afterwards probably did. There's a Warthog there, too, but if you don't move quickly you'll probably find that a burning hulk after the encounter as well. The piece plays until the final battle before you enter the tunnel, and my only complaint about it is that it's too short. If Halo 2 is supposed to the desperate, battle against unbelievable odds that forms the middle chapter of a trilogy, the music is going to have to carry the burden of building this impression, as at least in terms of scale, Halo 2's encounters seem very similar to the first game's. What's changed is the pace.
The ultimate problem with this level is not that there is anything particularly wrong with it-- it has a great mix of environments and units together with some fun scripted encounters, including your introduction to Halo 2's new, improved, tougher and more dangerous Hunters. It's only real flaw is that it fails to deliver the kind of cinematic exhileration that the E3 realtime demo produced. Even with the same stirring score behind it, the fact that the game can't count on events unfolding in the same way every time, as the realtime demo did, means that when that music swells dramatically you may be hunkered behind a burning warthog hoping instead of kicking Covenant butt, which in some ways ruins the moment.