Despite the fact that the Campaign mode of Halo 2 was extremely fun -- in fact, it's my favorite part of the game --, there are still some things I disliked about it.

1. Size, Pacing, & Structure of the Stages

Halo 2's Campaign had some improvements over Halo 1's. The terrains within each stage were more varied, making them less repetitive, and they looked so much better and more detailed in appearance. Combined with the excellent storyline and some very notable moments that were really cool, this made for an enjoyable experience. However it just seemed too short in duration. I finished it in a couple days on Heroic, as compared to several weeks for Halo 1 on Legendary (I only got to play about one day a week, though). This seems kind of paradoxical at first considering that the stages look on average as big as Halo 1's. However, it turns out that Halo 2 has fewer actual maps than Halo 1, even though it lists more stages: a total count of 13 playable (since The Heretic and Armory aren't really stages). All of the stages except Cairo Station are not distinct from each other and are actually sections of a larger "super stage," i.e. Outskirts/Metropolis, The Arbiter/Oracle, Delta Halo/Regret, Sacred Icon/Quarantine Zone, Gravemind/High Charity, and Uprising/Great Journey (the latter two super-stages being interspersed between each other). When you take this fact into account, it makes only seven distinct maps: Cairo Station, Mombasa, the Threshold Installation, Delta Halo part 1 (Master Chief's mission to kill Regret), Delta Halo part 2 (Arbiter's journey to the Library), High Charity, and Delta Halo part 3 (Arbiter's mission to stop Tartarus). Compare this to ten maps for Halo 1. Even though several stages shared geometry with another later stage (i.e. AotCR/Two Betrayals, T&R/Keyes, and Pillar of Autumn/The Maw), they were substantially different from each other in terms of gameplay, objectives, and atmosphere despite being superficially very much alike, and are spaced apart from each other by several other stages. This is quite unlike Halo 2's stages, which are simply halves of one long, continuous map. However, I have to admit that it's hard to tell whether the stages are collectively larger in terms of absolute size in Halo 1 or Halo 2, despite the difference in number. In fact, it becomes clear after playing the Campaign numerous times that the seemingly contradictory nature of Halo 2's stages is mostly the result of rapid pacing and very linear structure rather than the number or length of stages. Because of the linearity and rapid pacing, much of the Halo 2 Campaign sometimes feels only a couple of steps removed from an old-school run-and-gun shooter like Contra or Metal Slug, and certain scenes can feel almost like a rail shooter.

First, the issue of linearity. Despite the sheer size of the stages in Halo 2, the actual size of the playable areas seems relatively small. The pathways one must take to get from one part to the next are usually very narrow and congested, even in the parts that take place outdoors. Furthermore, there is typically only one pathway you can take to get from one point to another. Whenever there is more than one path to take, it really makes no difference in how one can possibly approach a particular situation. In Halo 1 however, there were plenty of wide-open outdoor areas, and often there were multiple pathways one could traverse to move to and from various locations. This gave a sense of size and openness regardless of the stage's actual size, and it provided for a relatively non-linear experience on many occasions. Perhaps the best examples of non-linear gameplay in Halo 1 are found in the stages Halo and Silent Cartographer.

In the stage Halo there were multiple ways to approach each of the primary encounters and mission objectives due to the abundance of open areas and multiple pathways. For example, you could face the initial wave of Covenant troops deployed via dropship, or you could simply run from them, shoot down one of the Banshees, and make your way to the rest of the stage. If you chose to fight, you could lure them across the bridge, or you could stay at the lower area near the waterfall and fight them there. When you arrive at the first set of buildings where Sgt. Johnson and the other Marines are at, there are several different ways of fending off the waves of Covenant dropped into the area. You could stay at the center building and wait for them to come to you, or you could move into the surrounding structures, coming at them from various angles, or you could simply charge right at them if you were feeling confident enough. Once you get the Warthog and made your way to the second half of the stage where you had to rescue the other Marines, you could pick each of the three sections in whatever order you wished. Each of those three sections were connected via the main river valley, with two of them connected to each other directly as well, and there was more than one way in or out of two of them. Also, if you didn't know the layout of the area, you could get lost and end up running around in circles.

In the Silent Cartographer, you could circle around the island until you got to the map room, but the doors to it would lock and you would then be forced to find the interior of the island and enter the security room to unlock the doors. Alternatively, if you already know where the security room is, you could simply go there first before making your way to the map room. Given the open nature of the island's exterior, you could approach either section from several different angles. Once inside the map room, you could fight your way all the way down to the bottom and back up, or, if you had an overshield, you could attempt to jump off the end of the bridge at the top down to the bottom area, which can save some time. If you took the long way, there was more than one route to take, and you could face your enemies in more than one way. You could have a straight up firefight, or you could opt for a stealthier approach, as you could sneak up on most of your enemies if you took the right route to the bottom (getting back to the surface was the tough part).

There are of course many other examples of more or less non-linear gameplay. There are certain occasions where you may have to backtrack or otherwise progress through a certain part of the level in a not-so-straight line fashion. Certain routes to the end of the stage may be forced upon you or become restricted if you haven't acquired a certain vehicle. Many encounters can be approached from several different angles, each with different possibilities. One route may give you the opportunity to skulk around unseen and avoid potential conflict, or you could simply fight your way through, or if that doesn't work, you could always try coming at your enemy from a different angle. While Halo 1 was not a truly non-linear game, large portions of the game could be described as "semi-linear."

None of the levels in Halo 2 give the same sense of non-linear gameplay. The player is regularly herded from one encounter to the next through very congested pathways and small arenas. Even in the outdoors levels, there is a sense of claustrophobia, and the player is highly restricted in their selection of where they can and cannot go. Numerous invisible walls and "instant-kill" zones keep the player from wandering too far out of bounds and exploring. Large sections of certain stages, such as Regret and Quarantine Zone, involve being transported to the next section on a rather small gondola or elevator that the player has little control over (hence the earlier "rail shooter" comment). Steep cliffs bound many areas, and there are numerous places where a relatively short fall will mean certain death, which is ironic considering the removal of fall damage. Thus, the apparent openness of many levels is mostly illusory. About the only parts of the game that are non-linear and provide opportunities for exploration and various approaches to combat are certain sections in Outskirts and Metropolis. I also thought the Off the Rock, Through the Bush, Nothing but Jackal segment on Delta Halo was well-designed and fairly non-linear, and had many different passageways. However, these were about the only exceptions to the rule. Rampancy's Narcogen summed up the differences between the levels in Halo 1 and Halo 2 thusly when he compared Silent Cartographer with Delta Halo:

"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 drop-off 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."

The stages are also structured in a way that results in every encounter playing out almost the same way regardless of which angle you approach it from, assuming you can even approach an encounter in more than one way to begin with. There were only a couple of exceptions. For example, Outskirts is one of the few stages that have multiple pathways through certain parts of the stage, and the aforementioned "Nothing but Jackal" segment allowed for several different approaches to the encounter. However, you usually end up only having the choice of whether you want to come at the enemy from the right or left side, and so each encounter plays out more or less the same regardless of which angle you approach the situation. There are few opportunities for stealth, sneak attacks, and the like, and so everything is almost always a straight up face-to-face brawl. You can't pick your fights nearly as often as you could in Halo 1. This highly linear gameplay that forces you from one encounter to the next also results in a game that feels overly fast-paced. This is further aggravated by the fact that you can simply blow through large portions of several stages on a vehicle without worrying about having your progress impeded by the enemy or some kind of obstacle.

While such a rapid pace and linear gameplay may be suitable for run-and-gun 2-D shooters and older FPSs, it certainly isn't suitable for a Halo game. The stages really could've used some improvement in their structural design and setup of enemy encounters. This is perhaps the most serious drawback of an otherwise excellent Campaign mode. There really needs to be more concerted effort to combine the aesthetic qualities of Halo 2's stages with the open stage designs and style of gameplay found in Halo 1's Campaign.

2. Difficulty

The first Halo was quite a challenging game, especially on Legendary. There are plenty of encounters that will give you pause, making you formulate an effective strategy rather than simply use brute force to blast your way through the enemy forces. However, the difficulty in Halo 2's Legendary is not the challenging kind of difficult that makes you think as well as act. Rather, it's the kind of difficult that makes you want to throw your controller at the screen in a fit of sheer frustration. When I first got the game, I quickly gave up trying to beat it on Legendary the first time around, opting instead for Heroic difficulty. (I did eventually get around to beating H2 on Legendary, and it was an immensely frustrating experience. I honestly doubt I'll try it again.) There are various things that contribute to Halo 2 Legendary's insane difficulty.

First is the fact that enemies are capable of absorbing an incredible amount of firepower while simultaneously dealing out huge amounts of damage against the player, even more so than in Halo 1. For example, you can empty almost an entire magazine of Battle Rifle ammo into a blue or red Elite before it will kill him, while he will easily be able to shred through your own shield in a split second with his own firearm. And don't even mention those white-armored Ultra Elites (argh!). An Elite can also withstand a slash from your Energy Sword, but he can easily kill you with a single smack to the face from his plasma rifle or carbine, which is also the case even on lower difficulties. Against any Elite rank in Legendary, unless you have some heavy weapons at your disposal, you pretty much either have to use a plasma pistol in conjunction with another weapon (due to the former's ability to drop shields with a single shot), or you have to stick them with a plasma grenade. The SMG/Plasma Rifle combo is also somewhat effective, but only if you're facing one of the weaker ranks and even then only in a one-on-one fight. Brutes have an insane amount of health and are damn near impossible to kill with any firearm unless you get a headshot with a BR, Carbine, or sniper weapon, fill them full of Needler rounds, blast them with a rocket or fuel rod gun, or stick them with a plasma grenade. They are also able to withstand a hit from the Sword while being able to kill you with one or two melee attacks. Even Grunts and Jackals have a lot of health. Unless you can shoot them in the head with a Battle Rifle or Carbine or blow them up with a grenade or rocket, it can take quite a few shots to drop one, and it can also take several melees to kill them unless you use the Sword, which is ridiculous considering that Elites can kill the Chief with a single melee despite not being much stronger than him. Also, especially when they're fighting in groups, Grunts, Jackals, and Drones are able to easily tear through your shields and health. Even the Flood are stronger; the Combat Forms can kill you with a single melee, while the Infection Forms now do far more damage when they come into contact with you. Enemy vehicles can also take quite a bit of damage. For example, when you're in a tank, a single rocket or tank blast can take you out, while it can take several of the same hits from you to kill an enemy tank. This is especially problematic given the fact that a vehicle's health is linked to that of its operator (see the section on vehicles below).

Another notable example is the addition of sniper Jackals. Having enemy snipers was a nice addition, but they are simply too difficult in Legendary. Not only with will they usually spot you far faster than you can spot them, but their accuracy is close to 100%. It is quite cheap when a Jackal, shooting from the hip right after he spots you, is able fire a particle beam clean through your brain before you even have a chance to spot him yourself, much less line up a shot. Even if you get the shot, a Jackal can take several body shots from a sniper weapon on Legendary, so you better hope you can get that headshot off or you might not survive. Combine this with the linear nature of the Campaign stages where you are normally limited to approaching the enemy from a single angle, and you've got a task aggravating enough to make even the most seasoned Halo veterans wish they never tried it on Legendary to begin with. To get past the several occasions in Campaign where you'll encounter sniper Jackals, you'll have to rely almost entirely on rote memorization and sheer luck. There's nothing skillful about this, it involves no strategy, and it's just plain unfair. Getting killed by sniper Jackals on Legendary is almost never due to carelessness on the part of the player.

Halo 2's Legendary doesn't give you the feeling that you fought a long and very hard, though not unfair, battle against a challenging enemy. It makes you feel like it's not even worth playing. It's nerve-wracking, tedious, frustrating, and seemingly impossible in many parts, and this discourages people from playing Campaign on Legendary as their standard difficulty level like they did in Halo 1. Heroic in Halo 2 is closer to Halo 1's Legendary in terms of how hard it was: difficult but not unreasonably so, yet a blast to play. Legendary in Halo 2 is just plain ridiculous, and it's not fun. There really needs to be some more extensive playtesting in Halo 3 to ensure that Legendary is hard without being cheap and unfair.

3. Boss Battles

I'm sorry, but it was rather cliche to use the old boss battle gimmick in Halo 2. It might work for some games, but not a military-themed shooter like Halo. If there are bosses, they shouldn't really be that much different from rank and file Covenant, except perhaps for better equipment, more shielding and/or health, and smarter AI. But there shouldn't be anything unique in their abilities or what the player needs to do to defeat them, unlike Regret and Tartarus, who both have attributes wholly unlike those of any other enemy. Against Regret, you had to board his hover pod and punch him to death. No other method of attack will work. (As an aside, he was supposedly going to have a unique special attack, which turned out to be a twin Hunter beam, but just colored yellow, so nothing special there.) Against Tartarus you had to wait for Johnson to drop his shields with a shot from his beam rifle before you attacked. Tartarus was the only Brute to have an overshield. His shield was also unique in the fact that it could only be disabled by Johnson's beam rifle. Oddly enough, if you have your own beam rifle, it will be completely ineffective against Tartarus' shield. Furthermore, if you manage to push him off the control room platform into the pit below (usually by using a Banshee), he is for some odd reason able to survive and reappear back on the platform. Like Narcogen said, "Just about everything wrong with the idea of a boss battle is embodied in this encounter: special weapons, special enemies, special rules. Everything you've learned about how to play Halo up until that moment goes right out the door, replaced by a mini-game where you have to repeat in lock-step a series of actions in order to reach your objective." The boss battles with Regret and Tartarus, characters governed by unique sets of rules, created a sense of disconnect with the rest of the game. At least the Heretic leader could be fought more or less like an Elite Ranger, albeit a tougher one with two holographic decoys.

4. Other Enemies

Not that it drastically effects gameplay, but there are minor changes to a couple of enemies that I dislike. First off are the Hunters. In Halo 1, they had a fuel rod cannon identical in function to that wielded by Grunts. In Halo 2, they are now armed with a weapon that, while described as a fuel rod gun, fires a green energy beam different from the fuel rod guns wielded by Grunts or those mounted on Banshees. Personally, I find that the Hunters' new beam attack is less dangerous and intimidating, not only in its capacities as a weapon, but also in the way it looks and sounds. Other than the changes to their weapon, I really liked the new and improved Hunters, as they were tougher to kill and had better hand-to-hand offense.

Also, there are a couple of changes made to the Flood that I didn't like. First off, the Infection Forms attack in fewer numbers but do more damage individually. This makes it to where the player has to focus on fewer of them and regard individual ones as a somewhat greater threat. I thought it was better to have the larger swarms of Infection Forms seen in Halo 1. They may have been weaker, but they were still dangerous collectively and were also much creepier. Secondly, the Carrier Forms have a smaller blast radius when they explode. The burst also projects less force and seems to do less damage. This not only makes them less of a threat, but also makes them less effective when the player attmepts to use their ability to explode to his/her advantage.