After the Metroplis closing cutscene, most fans were getting set to break out the pitchforks and the torches to protest that Halo 2 was denying them what they had expected to get-- a long, drawn-out, large-scale invasion of Earth to battle against. That's a shame, because the next two levels, Delta Halo and Regret, are where Halo 2 really starts to shine, although there still are a number of differences from the first game that may eventually prompt fans to fire up the prequel.
The boarder-repelling scenario in Cairo Station was largely a reworking of Pillar of Autumn; the recovery from a crash and link up with other forces part of Outskirts is a repeat of Halo's second and titular level. In Delta Halo we get the closest thing to a repeat of the opening parts of Silent Cartographer-- taking and holding a beachhead while under hostile fire to allow reinforcements to land.
As with everything in the new game, the terrain of installation 05 that you hard-drop onto is insanely detailed. Environments generally offer a lot more cover than those in the first game, which is good in terms of gameplay but does make the player feel slightly claustrophobic, as if somehow the world you're in is both larger and smaller at the same time.
The landing zone portion that starts this level combines most of the best elements of the first game with enhancements from the second, at least in terms of vehicle-less play; about the only thing that seems out of place is how small the area is, even compared to the area in Silent Cartographer.
There are multiple options for approaching the battle; support from friendly troops, a good mix of enemies (Elites, Grunts, Jackals, and turrets) and enemy reinforcements. There are several places to hide, either in the nearby structure or in the drop area. In short, unlike many parts of Halo 2 that seem to play out basically the same way no matter what you do, this part can end up being quite different. It's also possible to flee the area towards the next encounter; between the landing zone and the bridge guarded by Wraiths and Ghosts is the game's second and smaller "sniper circle" area with several beam-rifle armed Jackals.
If you play through the landing zone sequence to its logical conclusion, you'll get a Warthog; and even though it is marginally more difficult to get vehicle kills in Halo 2 than in the first game, this area is still not that hard if you have a vehicle.
However, on Legendary you may find yourself running low on suitable ordinance in the landing zone, depending on how you play it. One interesting option is to flee to the sniper circle, take on the Jackals, and then go back to the landing zone and clean up with the beam rifles. This works best if you've got grenades and a battle rifle; at that difficulty you can't let one sniper get in a clear shot, or you're history.
The next encounter combines parts of the underground lightbridge scenario in the Halo level with outdoor tank-on-tank action from Assault on the Control Room. However, the area is cramped. There's really no choice in how to approach the assault other than to choose between available vehicles; basically you go across the bridge and get attacked by Wraiths and pairs of Ghosts. (Banshees come before that, after the Scorpion arrives but before you cross the bridge.)
As in Metropolis, many of the areas once you get the Scorpion are essentially linear; you drive the tank through pretty areas, get assaulted by Ghosts, harassed by motley ground troops, and eventually reach a place where you have to go through a door too small for the tank and have to abandon it. The experience is visceral, but the way it plays out leaves me wondering if it will ever have as much replay value as AotCR does.
After abandoning the Scorpion and traipsing through some ruins, you'll arrive at another sniper-laden "tough bit" that is probably one of the more frustrating encounters in the game, along the lines of the second hangar area in Cairo Station.
The frustrating part of it is that successfully beating it, unlike areas like the hangar, seems to be based on accurately predicting when and where new enemies will appear; something you can only do after playing the area and getting killed, so you know where and what to look out for next time.
The area starts out with a few snipers, then jackals and elites from various areas. If you're lucky, you'll spot the snipers moving into place and can take them out and/or take cover appropriately. However, as you progress through the area, at least three times (on Legendary, anyway) a group of up to six drones will descend from the skies. Out in the open, you don't stand a chance no matter what you're armed with.
Annoyingly (or luckily, depending on your logic) this occurs right after a checkpoint, so it's very easily to get frustratingly stuck in an endless loop where you're stuck in the open, drones descend, and you scramble for cover onlyi to die in about three seconds. For whatever reason, this doesn't seem to trigger an earlier checkpoint no matter how many times it happens.
But what really takes the cake here is that even once you know the drones are coming, if you run for cover and hide before they arrive, it scarcely makes any difference. The drones seem scripted to converge on your location regardless of whether you can be seen or not (either that, or drones have x-ray vision). Hide in a tunnel, behind a rock, in the waterfall, or run for the hills-- it doesn't matter, they'll find you and surround you and kill you just the same. The strategy suggested by several legendary walkthroughs is to hide in the tunnel, watch both ends, and use grenades. After several experiments I found that the second-level tombstone rock actually provided better cover; and that if you manage to duck there for a few moments, the drones' initial rush attack script seems to end and they go into patrol mode, after which you can isolate them and take them out at your leisure.
That's nearly the end of the level, as the next encounter leads you down a ramp into the first of a series of structures that makes up the Regret level.
Like most of Halo 2, Delta Halo is extremely pretty and very detailed; however, the level itself consists of three major encounters outdoors, one of which, the middle area, feels very small and cramped. The island motif of Silent Cartographer was, in a way, a much more clever and effective method of restricting the player's movement to a relatively small area while giving them the impression of playing in a large space. Delta Halo doesn't give that same impression; the initial LZ borders a cliff dropoff that will kill you, and the level keeps you boxed up the rest of the way until it shepherds you inside a structure. Even the out-of-play areas, like those in Metropolis, are clearly demarcated with invisible walls. Silent Cartographer also had such walls, but much further away. The overall impression is that of a less expansive, if more detailed, romp over the surface of a Halo installation.
That aside, it is a very enjoyable level, and one I plan to look for more replay scenarios in.