The second chapter of StarCraft II, focusing on Sarah Kerrigan and the Zerg.After the events of StarCraft II: Wings of Liberty, Sarah Kerrigan, formerly the Queen of Blades, has been mostly de-infested, leaving her with her original personnality back, but only fragments of her memory as the leader of the Swarm and remains of zerg abilities. The Zerg Swarm, now leaderless, has fragmented into splintered, unorganized factions. While Kerrigan is now hungry for revenge against Mengsk, Raynor tries to convince her to move on. Unfortunately, Mengsk comes after them first. Using what remains of her abilities, Kerrigan goes on a quest to reclaim the Swarm and use it to crush Mengsk once and for all.Descriptions below may contain unmarked spoilers for StarCraft II: Wings of Liberty.
All the Dominion forces inside the ship Mengsk blows up in an attempt to kill Kerrigan. As you run to save Raynor while it's falling apart, you hear them panicking, horrified that their emperor is sacrificing them in such a way. Calling this a Kick the Dog for Mengsk would be an understatment.
Subverted with Mengsk himself. When at the end of the game he is trapped in his palace, with Zerg invading his city and Kerrigan coming for him, you might feel sorry for him... and then, he does a last Kick the Dog moment by torturing Kerrigan with the Xel'Naga artifact. After this point, you definitely feel relieved to see Kerrigan kill him once and for all.
Anti-Frustration Features: Town halls now display how many workers are gathering resources vs. how many is optimal. The same applies to Vespene Geysers (because You Require More Vespene Gas)—worker count visible without clicking (previously one had to select the geyser-building to see harvester counts while town halls had no count shown at all). This feature was also ported back to Wings of Liberty, and applies to both multiplayer and the campaigns.
Some features intended to reduce frustration may cross into Stop Helping Me!, depending on the player. Fortunately, for some of these (such as interface options) the player can go into the settings and set them back to the old style, if they are more comfortable that way.
A common Zerg tactic in multiplayer prior to Heart of the Swarm was using 4 infestors in an overlord to harass enemy bases, which was often called a "Four 'Festor Hit Squad". The mission where you gain infestors in the campaign starts you off with... 4 infestors.
Another common tactic (usually considered a cheese) for Zerg is what's called a "6 pool" build: with the initial six drones, create a Spawning Pool and try to get a handful of zerglings out the gate before your enemy has any defenses deployed. In the very first mission in HotS, you're instructed to create a hive, six drones, one spawning pool... and use nothing but zerglings for the rest of the mission.
On the final Char Mission, a random soldier might call out "So many Banelings!" if you attack with enough of them.
The mission where you control the Hyperion is very much inspired by the fan-made Custom game Star Battles.
Asshole Victim: With all his Kick the Dog moments over the course of both Wings of Liberty and this game, it's hard not to feel relief when Kerrigan finally kills Mengsk.
Asteroids Monster: One of the upgrades for Banelings allows them to do this (by killing an animal that had this ability), becoming two smaller Banelings that do less damage. Abathur notes that doing this further results in sentient slime.
A Taste of Power: The Evolution Missions, which allow you to test the campaign-only mutually-exclusive upgrade sets in a controlled environment before committing to picking one.
Autobots, Rock Out!: Pretty much anytime in the campaign that you're rolling out to destroy the enemy opposition on the map, expect that awesome music from the trailer to play.
Zerglings can become either raptors (cliff jumpers) or swarmlings (3 per larva, build instantly). Your choice is now to Zerg Rush from behind the enemy base or just a bigger rush.
Banelings can split into smaller banelings on death, or become cliff jumpers too. Have fun either watching even bigger explosions or sending suicide bombers to the back of an enemy base.
Swarm hosts can either spawn flying locusts or teleport instantly between creep.
Roaches have a choice between a Spawn Broodling ability or paralyzing slime.
Ultralisks either produce corrosive gas clouds or resurrect on death.
And this is not listing Kerrigan's abilities, which including an ability that is effectively an instant-hit Yamato Cannon, produce two Drones from one egg, cause Creep to give regen and attack rate bonuses to units as well as spread further and faster, and finally, a Fantastic Nuke.
Also, most units have three upgrades you can choose from between missions (though many are the equivalent of the researchable upgrades in a standard game). Upgrades include making zerglings roughly three times as fast as marines, having mutalisks bounce off twice as many targets or doing horrible, horrible things to armored enemies, making ultralisks perform burrowed charges, or having baneling explosions heal nearby zerg troops.
Back from the Dead:Alexei Stukhov, The UED admiral killed by Samir Duran during the Brood War mission "Patriots Blood", makes a surprise reappearance as an infested terran at the start of "Infested".
Some of the actual campaign units can do this as well. Ultralisks have the choice of gaining an ability that resurrects them on death, and Zerglings can do the same if Kerrigan has the appropriate ability.
Arcturus Mengsk is disdainful of his soldiers and citizens in a manner that would make Darth Vader uneasy. Vader at least cared about his son; Arcturus ordered his men to kill Valerian just because he was on the same ship as Kerrigan.
In one mission where Kerrigan attacks a Dominion ship (Raynor is a prisoner onboard), Arcturus detonates the whole ship, with thousands of his own people still aboard. The panicked and horrified reactions of his men are pretty jarring, even while you’re in the process of fighting them.
Arcturus: Everyone aboard this ship is willing to give their lives to stop you, Kerrigan. Bridge Crew:Wait, what did he say?? Bridge:[self-destructs]
Arcturus goes even further during the invasion of Korhal, where he calls down nukes inside a major metropolitan area with no concern for collateral damage. When he said "I'll rule this sector or see it burnt to ashes around me!" it was not hyperbole in the slightest.
Valerian: My father is willing to sacrifice any piece on the chessboard, so long as he takes the queen.
It is implied that General Warfield could have defeated Kerrigan on Char, if the Xel'Naga artifact hadn't mysteriously gone missing (given its power in the final mission of Wings of Liberty, this is very likely). It's revealed at the end that Mengsk had it in his palace the entire time, meaning he deprived Warfield of his only chance to survive just to protect his sorry hide.
Battle Couple: Deconstructed between Raynor and Kerrigan. At first it's shaping up to be this, but when Raynor saw her after her trip to Zerus, he felt that Kerrigan was just reverting back to the old Queen of Blades and angrily ends their relationship. Eventually after Raynor overhears the extreme lengths Kerrigan is going to avoid civilian casualties in the invasion of Korhal, he eventually decides to join her at the last minute and ends up saving her when Mengsk tries to reactivate the Xel'Naga artifact. While both of them know they cannot be together anymore due to what lies ahead regarding the prophecy of the Dark Voice, they still do love each other.
Beam-O-War: Kerrigan engages in one with Narud during the infiltration of Skygeirr Station. There's a convenient beam-o-meter at the top of the screen during the mission!
Berserk Button: Do not use Kerrigan's love of Jim Raynor to attempt to manipulate her, unless you want to die a very ugly, very violent death, very quickly.
Big Damn Heroes: At the end of the game, Jim Raynor bursts in and destroys the trigger for the Xel'Naga artifact Big Bad Mengsk is using to torture Kerrigan. Raynor crushes the remote in his power-armored fist (while it's still in Mengsk's hand) before grabbing Mengsk by the face and hurling him a good ten feet across the room.
Raynor: CHANGE OF PLANS!
Bigger Bad: Like in Wings of Liberty, the Dark Voice is pulling the strings behind the scenes. This game, we get more detail: He is Amon, a fallen Xel'Naga dead for countless centuries before Narud brought him Back from the Dead.
Bittersweet Ending: Kerrigan gets her revenge on Mengsk and the Swarm is free of Bigger Bad Amon's influence. However, Kerrigan is forced to leave Raynor behind to prepare for the coming war with Amon and the Hybrids.
Black Comedy: While Raynor's prison ship is blowing up, you can find a squad of Marines fleeing. One calls out "get to the escape pods", only for the Medic to correct "it's the prison level, there aren't any escape pods!"
Zerg don't act out of malice towards other races; they just have difficulty understanding any morality beyond "Everything that is not zerg is a threat and as such needs to be assimilated or destroyed." No news for those who paid attention to the story before (the original, pre-Brood War zerg campaign, as in BW Kerrigan did really act out of malice), but still, good to know that the writers remember this.
Kerrigan: It's that simple? Izsha: For a zerg, it is.
In fact, it's suggested that they see assimilation as a good thing to do to other species. In one dialogue, Zagara, who at this point has become as smart as a human, mentions she pities the humans for being "alone inside" due to lacking a Hive Mind and want to "help" them through assimilation.
Same goes for the Primal Zerg; they see nothing wrong with devouring each others to evolve because they live by a Social Darwinist-like code, and consider the concept of devouring or being devoured to become more powerful as their inheritance.
Book Ends: The game begins and ends with Kerrigan saying I am the Swarm.
Boss Battle: Several. Complete with associated sub-tropes.
Flunky Boss: Primarily Brakk and Slivan. Kraith, Yagdra, the Archangel, the Kel-Morian ship, and Zurvan also do it to lesser degrees.
Final Boss: The Odin, one of the last obstacles before the final mission objective.
Brick Joke: In Wings of Liberty, Donny Vermillion reports about lemon juice possibly being useful against zerglings. In Heart of the Swarm, Abathur makes an off-hand comment about solving the zerglings' allergy to lemon juice.
Call Back: A number of events from previous StarCraft works play a role in the plot of Heart of the Swarm
The Odin turns out to have been re-acquired by Mengsk for palace defense after Wings of Liberty, along with the Xel'Naga artifact.
Alexei Stukov from Brood War shows up Back from the Dead to help Kerrigan in the endgame of Heart of the Swarm.
Additional elements of the Brood War secret mission "Dark Origin" feature in Heart of the Swarm.
A few missions utilize this as well: in Wings of Liberty, the mission "Outbreak" involved the player cycling between defending a base while waves of Infested Terrans spawned from buildings and attacked, and destroying the infested buildings while an environmental effect removed all of the enemy units from the field for a short time. In Heart of the Swarm, the mission "Infested" presents the same scenario, but with the roles reversed; now it's the player infesting buildings which spawn waves of units to attack an enemy's base, and every few minutes an environmental effect comes into play, removing all of the Infested Terrans and requiring the player to defend them against enemy attackers. Some of the same lines will even be used in both missions, as well as the Infestor being the featured unit both times.
For the first time since Brood War, Jim has finally mentioned Fenix, and Kerrigan reminds him that he swore to kill the Queen of Blades after she killed Fenix - a vow he seemingly forgot about during Wings of Liberty, a cause for much of the Broken Base that Wings of Liberty introduced.
If you helped Nova in Wings of Liberty, she'll mention it in the second mission. Likewise, if you sided with Tosh, he will get a mention during the briefing for the mission "Conviction".
Likewise, after you recruit Zagara, she will talk about either the Nydus network or the space platform destroyed, depending on your choice of the penultimate Wo L mission.
Behemoths have been mentioned in the novels as the vessels used for interplanetary travel by the zerg, and the Leviathan was a boss in Wings of Liberty. They've been combined here.
On Korhal, Mengsk shows that he kept some traditional squadrons and relics from the Confederacy intact under his Dominion. Notably, an elite marine and Goliath commando squad are known as the Sons of Korhal, and the Battlecruiser fleet that defends Augustgrad is known as Alpha Squadron.
A number of the biographies to campaign-exclusive units make reference to strains and characters forgotten since Brood War, the Hydralisk evolution mission especially, where the Impaler is based on the same strain as the Sunken Colony, and feral Lurkers are located at one of Daggoth's former breeding grounds.
An amusing one in the second mission that doubles as an Easter Egg; if you start the mission and do nothing for a full minute, Kerrigan comments to Raynor that, six years on, he's still a pig! A callback to their very first conversation in the original StarCraft.
The reason Kerrigan doesn't kill Abathur despite his role in her initial transformation into the Queen of Blades.
This is presumably also the reason Jim Raynor doesn't kill Kerrigan after she's re-infested herself, despite how angry he is with her; if Kerrigan dies, the galaxy is doomed, and he knows it.
Catapult Nightmare: Downplayed. The intro of the game has Kerrigan twitching away quite violently after having a Nightmare Sequence involving the Swarm invading the Terran capital world of Korhal, but her looking around and sitting up is a bit more subdued.
Character Development: While no longer as evil as she was in Brood War, Kerrigan still starts out as a Villain Protagonist obsessed with revenge against Arcturus. The whole point of the game is to gradually develop her into a more heroic character.
Chekhov's Gunman: Dehaka. Both Zagara and Izsha question Dehaka's presence on the Leviathan, but Kerrigan strangely allows it. Dehaka does little more than seek new excuses to say "essence" for the second half of the game. When Kerrigan later calls on Dehaka to destroy a Psi Disruptor on Korhal, it shows just how much of a Magnificent Bastard she is, knowing to keep this partiuclar ace up her sleeve.
The Cuckoolander Was Right: Newcaster Donny Vermillion's ridiculous claims in Wings Of Liberty that zerglings are vulnerable to lemon juice and that Raynor had teamed up with the Queen of Blades to overthrow Mengsk turn out to be true in Heart of the Swarm.
Coincidental Broadcast: Sarah learns of Jim's "death" precisely at the moment where she's getting desperate, waiting for him to show up.
Color-Coded for Your Convenience: Zerg units can be upgraded into one of two forms, with a predominantly green or purple look. The green ones tend towards brute force (Ultralisks with more damage and an auto-damage attack, Banelings that split into smaller Banelings, Brood Lords that pound the enemy and Spawn Broodlings, Swarm Hosts that release flying locusts, Impalers that ram a very unfortunately-colored spike through enemy armor), purples tend towards sneakiness (Ultralisks the resurrect, Banelings that jump over the heads of melee units, Vipers that abduct the enemy and prevent them from attacking, Swarm Hosts that teleport anywhere there's creep, Lurkers that damage multiple light-armored units).
Continuity Nod: One of Stukov's lines is "Those who are about to die, we salute you." This is basically the English translation of the first line of the Brood War Aria, which is playing in Admiral Du Galle's quarters while he and Stukov have a nice chat.
Convection Schmonvection: the Boss Rush level where you fight three Zerg pack leaders (IE final Zerus mission) has still pools of water within a few yards of leaping pools of lava. Though it is the Zerg's homeworld so they could be spawning pools.
Crosshair Aware: There are full-fledged boss fights now, not merely battles against units with a bit more HP. They each project red lines and crosshairs showing where they're about to attack so you can avoid them.
Cutscene Power to the Max: In the cutscenes, Kerrigan smashes whole groups of Humongous Mecha instantly. She can't quite do that during game play, however she's not too much less powerful (several missions can be won with her alone) it's not as noticeable as usual.
After the bossfight with Zurvan, Kerrigan flies up in the air to deliver the final blow. Likewise, at the very end of the game she's seen flying up on nothing but her psychic powers, which she never does in-game.
Curbstomp Battle: The "evolution" missions. Abathur sends Zerg evolution strains to other planets to wreck havoc on "test subjects". The Ultralisk one involves raiding laboratories at Korhal, the second one involving regenerating Torrasques that get powered up by Mengsk's initial nuclear missile.
Damn You, Muscle Memory: Kerrigan's active abilities are mapped to Q, W and E on the keyboard, and her strongest ability to D. Hands up how many MOBA players keep trying to hit R instead (and burrowing their entire army as a result)?
For that matter, the hero icon is in the top left of the screen (where it was in Warcraft III), when Wings Of Liberty shifted it to the bottom right. Confusion may ensue.
Death Is a Slap on the Wrist: Except for a few missions with the objective "Kerrigan must survive" (which is usually there if you have no base on that particular map), whenever Kerrigan dies, she is automatically resurrected at the hive cluster a little while later.
Same goes for secondary heroes in missions where a base is available.
Defrosting Ice Queen: Subtle, non-romantic example with Kerrigan towards the Zerg. At the beginning of the campaign, she is rather cold and aggressive, almost abrasive, toward her subordinates. She gradually warms up a bit toward them as the story goes on and starts treating them more human-like. By the end of the campaign, she express satisfaction about Zagara being her potential heir if she dies, and even express sympathy for Abathur, of all people.
During the first Char mission, Zagara will rant at you if you do certain things which especially impress or anger her, such as forcing her to retreat while not including Kerrigan in the attack force or not even using her to defend your base from attack.
It is possible to do limited Sequence Breaking by going to Zerus before Char. Normally, Zagara will command the swarm while Kerrigan undergoes metamorphosis. However, if you have not done the Char missions and acquired Zagara, Izsha will defend instead. Dehaka also has dialogue for if you if you recruit him before going to Kaldir or Char and talk to him once you do. Blizzard even rendered two separate versions of an FMV depicting the same exact scene (where Kerrigan kills Warfield), one with the human-looking Kerrigan and one with the primal Kerrigan. The dialogue the protoss executor has upon first encountering Kerrigan on Kaldir also differs based on whether or not Zerus was visited first.
When Kerrigan "dies", she tunnels back to base and enters a cocoon to regenerate. If at any point during the mission she's scripted to talk, her portrait is changed to show her in the cocoon, with a distortion to her voice. Putting off early missions until she becomes the Primal Queen of Blades also uses the appropriate portrait and voice effects for her dialogue in the same manner.
During a mission in which Infestors feature prominently (creation of "virophages" on platforms) while being equipped with permanent mind-control, Blizzard locks out creation of terran buildings should an SCV be captured via Infestor. So yes, a player can amass a terran army by stealing units, but s/he can't build an entire force of terrans and use them to sweep the platforms. (The SCVs can still repair mechanical units, though.)
Averted in an installation mission aboard a prison spaceship where it is possible early on to capture a Raven using an infestor and fly it into the inaccessible latter half of the level, the part the player is supposed to visit only after Mengsk triggers the self-destruct and the prison ship starts falling apart.
Blizzard finally fixed the bug where if you are playing one race in another race's interface, the race calls out for the wrong supply type. (I.e. it used to be if you were playing Zerg but had a terran interface due to a custom game, being supply-blocked would ask for supply depots when it was really overlords you needed.) Now all 3 races can call for all 3 supply types.
Post-mission summaries vary by mission and often list statistics that are either helpful in evaluating how well the player did in regards to an achievement or simply interesting if one tries to play the mission in a specific way.
During the opening mission, you get three types of units to control. You're supposed to use zerglings for combat outside the temporary hive cluster, and any attempts to move the Overlords outside the initial test chamber are blocked by the game. You can, however, choose to send drones into combat, and if they manage to kill a unit in a certain part of the labs, Valerian will comment on that.
Kerrigan, call off your-! Drones. You're attacking with drones.
Even funnier is the fact that you can win using nothing but drones.
Easily Forgiven: Averted with Kerrigan; the Protoss, when finding out she is back, immediately attempt to call their fleet to eliminate her, Mengsk wants her dead no matter what even when she is not leading the Swarm, and even Raynor, who was willing to forgive her as her regular self, loses it when she turns back into the Queen of Blades, to the point it takes until the end of the game for him to finally forgive her once and for all. Zeratul does help her by guiding her to Zerus, but he makes it clear that he doesn't forgive her crimes toward his people and only helps her that much because of the Prophecy.
Elite Mooks: The whole of the enemies final mission Reckoning Day, consisting of the elite of the Dominion army, which are stronger than the usual Terran units.
Though Raynor's Raiders have elite units of their own when they join Kerrigan.
Two of the Primal Zerg are beefed-up versions of the primal Ultralisk and the Swarm Host respectively (where the Host spawns tiny attackers, the primal one spwans Banelings).
Even Evil Has Standards: While she is obsessed with revenge against Mensgk, and willing to slaughter entire armies of Terran to reach him, Kerrigan's attitude while doing so is a stark contrast to what she did in Brood War. She tries to avoid unnecessary casualties as much as she can, even agreeing to give Valerian time to evacuate Korhal's civilian population before her attack, even though this makes it more difficult for her, stops backstabbing her allies and orders Abathur to stop experiments on human subjects, amongst other things. Whenever she does something that could be considered amoral, she is usually forced by the consequences and doesn't particularly enjoys it. Of course, given that she is leading the Zerg, amoral circumstances tend to be a frequent occurrence.
Evil Is Not a Toy: Invoked; in the first mission of the game, Valerian has Kerrigan "test" her control over the Zerg. Kerrigan instead grows an army of zerglings and wrecks the lab, before sending the Zerg she created into holding cages, to show Valerian the dangers of trying to control a chaotic race like the Zerg. She does deliberately avoid civilian casualties, and Valerian is smart enough to take the point.
She also chooses not to control them in the following mission and is rather reluctant to do it in the third.
Also invoked when it's revealed Arcturus is helping Narud to create Hybrids. He apparently hopes to use them against Zerg and Protoss, but Stukov is pretty much convinced he would never be able to control them.
Expansion Pack: The first of its kind released into the mainstream market for a very long while. Heart of the Swarm features a ton of new content, and a new campaign just as long and involved as the first (i.e. way more than your average modern DLC package) for less than the cost of Wings of Liberty. On the other hand, it can't be played without the base game.
Explain, Explain... Oh, Crap!: While wondering how Narud could hope to get enough power to resurrect Amon, Kerrigan and Stukov come to the conclusion he may already have by using the power she lost after being deinfested.
Eye Lights Out: Used symbolically rather than literally during the death of General Warfield. Already fatally wounded, Kerrigan kills him and leaves him lying where he fell. The camera remains on him as she walks out of the shot, and after a few seconds the headlights on the chest of his Powered Armor flicker and die out.
Fantastic Nuke: Kerrigan's Apocalypse power is functionally identical to a Terran nuke.
Except Zerg are Friendly Fire Proof when it comes to Kerrigan's Apocalypse - more than Terran units can claim where nukes are concerned.
As the Queen of Blades in Wings of Liberty, Kerrigan's Glowing Eyes of Doom were yellow-orange, as were her abilities. In Heart of the Swarm her eyes still glow orange at first but her abilities are blue and upon becoming the primal Queen of Blades her eyes glow purple, showing she's been fully cleansed of Amon's influence.
The same applies to the Swarm in-game. At first your army will be orange but after Kerrigan achieves her primal form thus cleansing herself of Amon's influence, your army will be purple from that point onward.
Grey and Grey Morality: Everyone is a deep shade of grey (the only redeeming factor in most cases is that everyone is looking out for their own), with only Raynor or Valerian's factions being close to white. This gets discussed when Kerrigan talks to a Protoss prisoner early on and gets asked why she attacked what were essentially researchers and colonists minding their own business.
Lasarra: Kill thousands to save yourself? Is that how you justify this? Kerrigan: I justify nothing. There is no moral high ground here. Your people have killed billions of Zerg. We are all covered in blood; there may be more on my hands than yours but in the end we are both killers.
Guest Star Party Member: Some missions involve controlling a hero other then Kerrigan, such as a Broodmother, the Hyperion, or Alexei Stukov.
Harmless Freezing: Occurs for Kerrigan, Zerg and Protoss on the first Kaldir mission (which is noted to be only slightly less cold than space). When frozen you are vulnerable to creatures who can resist the flash freezes, whose essence you seek so you and the Swarm can also resist it. In reality, such an environment would kill you or at least seriously maim you (i.e. lost extremities) from severe frostbite, even if you are a powerful psionic entity or have a Healing Factor.
Hollywood Tactics: Kerrigan's broodmothers aren't particularly smart, not really being able to think of tactics more complex than "send everything we've got at them." Kerrigan, annoyed at this, orders for their intelligence to be upgraded to compensate. When told this might make them dangerous to her, she insists she needs her minions as dangerous as possible.
Kerrigan has gone from the most powerful being in the sector with entire armies at her beck and call to a half-infested terran with nothing.
The Zerg swarm has gone from nearly conquering known space to dozens of fragmented broods hiding on backwater worlds now that Terrans have crushed their primary hive cluster on Char.
Hufflepuff House: Finally averted with regard to the Umojan Protectorate; the first couple of missions are set in one of their science facilities before a Dominion attack forces Kerrigan, Raynor and Valerian to flee.
The Kel'Morians also show up in a minor role later on.
Idiot Ball: My dear Emperor Mengsk, you thought of hiding a trump card to deal with Sarah, and you forget to factor in a man who has been a designated terrorist for 4 years, is in the current battle in front of your palace AND has scores to settle with you? Smart, Arcturus. Real smart.
I Love Nuclear Power: Abathur succeeds in making this trope real for Zerg by having Ultralisks draining energy from an expermimental nuclear strike to evolve into Torrasques.
I Need You Stronger: Non-villainous example, Zeratul assists her in seeking more power (after she's just finished slaughtering a colony of basically peaceful Protoss civilians, no less,) so she'll be strong enough to counter Amon.
Similarly, on Zerus, Zurvan helps Kerrigan to ascended to Physical God status and absorb the pack leaders So that she will make a meal strong enough to spur his evolution.
Late Arrival Spoiler: The official website's preview of Heart of the Swarm gives away the ending of Wings of Liberty, specifically, Kerrigan being de-infested.
Leaning on the Fourth Wall: When breaking into a lab, Kerrigan notes how heavily fortified it is and comments, "Just getting inside will be an achievement." Sure enough, the achievement for completing the ensuing mission is named, "Just Getting Inside".
Loyal Animal Companion / Right-Hand Attack Dog: A strange example. In a few cutscenes, Kerrigan is accompanied by a particular zergling with a broken horn. Likely a reference to Scar. Depending on how Zerg reincarnation works, it might actually be Scar himself.
Morality Pet: Raynor's influence keeps the zerg side of Sarah's nature in check, preventing her from relapsing into a megalomaniacal omnicidal maniac. Once he's no longer around, she jumps off the slippery slope into a Roaring Rampage of Revenge that gives little consideration for collateral damage. Once Raynor is rescued, he, combined with his crew, is able to soften her edges again.
After she kills Warfield at the end of the Char missions, Kerrigan respects his final wishes and spares his men, a marked change from her treatment of Dugalle at the end of Brood War and the Protoss colonists on Kaldir.
After cutting a swath of destruction to get to Mengsk on Korhal, Kerrigan also respects Valerian and Raynor's wishes, and gives civilians multiple chances to escape the Zerg onslaught.
Neck Lift: Early in the game, Kerrigan uses her psionic powers to lift Valerian Mengsk into the air by the neck.
Never Forgotten Skill: Kerrigan is given a ghost gun by Raynor, the same model she had in the original Terran Missions way back in Starcraft I. She has clearly not forgotten how to shoot with it, which is impressive, considering that she had spent four years as a melee character and a human/zerg hybrid. Actually somewhat justified, in that besides muscle memory Kerrigan has very little recollection of intervening events, so it's like she never stopped using the rifle.
The event takes place in Wings of Liberty, but The Reveal comes in Heart of the Swarm: If you use a device of uncertain origin to depower a titanically powerful being, where does all that energy go? Specifically, Narud used the heroes to turn Kerrigan back into a human. Not only did it remove one of the biggest threats to his plans, but he had Hybrids standing by on Char to collect the energy released, and feed it into Amon's resurrection. Whoops. He hadn't planned on Zeratul leading Kerrigan to Zerus and starting her on the path to becoming the Primal Queen of Blades, though
Even worse if you took advantage of the bug that allows you to repeatedly collect artifacts to sell to Narud in order to buy all the upgrades. You directly helped Narud ressurect Amon by giving him more artifacts.
Kerrigan, while still eager to get her revenge, didn't want to go back to leading the Swarm at the beginning of the game, and actually was unconfortable with controlling them. Had Mengsk not broadcasted fake news of Raynor's death, he would have just ended up dealing with a powerful but lone ghost assassin, who while dangerous on her own, would have still been less of a threat than a revived Queen of Blades leading the entire Zerg Swarm.
Had Mengsk not taken the Xel'Naga artifact from Warfield, Kerrigan might have lost while fighting on Char.
A minor one : Mengsk gives the order to use an experimental nuke on escaping Ultralisks...which changes them into zombies with the ability to resurrect again and again.
Nintendo Hard: The "Mastery" achievements, which require you to perform a task in a mission on Hard mode, can get hair-pullingly annoying. Many turn the level into a Timed Mission, and the timer is not generous in such cases. And many have the objective of destroying an enemy base or key building in a time limit, and as expected, enemies on Hard mode are much more difficult with stronger and more numerous units. For example, the Mastery achievement for the final mission is to destroy the Odin before Mengsk sends it against you. This will occur around the 22-23 minute mark, giving you only a 20-minute window to effectively complete the entire mission, since the Odin waits about ten feet from Mengsk's palace door.
There are, however, clever tricks the player can employ to make certain achievements much easier; in the example given, giving your Mutalisks a damage bonus against armor then sending a fleet of them circling around the left edge of the map allows the player to snipe out the Odin long before the 22-minute time requirement, allowing the rest of the mission to be played normally.
Not So Different: Kerrigan feels this way toward Alexei Stukov, due to both being infested Terrans who got experimented on.
Off Model: When Raynor shows up at the very end, his hair has gone entirely back to dark brown.
Order Versus Chaos: The main difference between the space-faring Swarm Zerg and the Primal Zerg on Zerus is that the primals compete with one another constantly to keep evolving, while the Swarm only devours non-zerg aliens.
Pay Evil unto Evil: Kerrigan's entire Roaring Rampage of Revenge against Arcturus. All the pain, destruction and death he wrought to build the Dominion is returned as Kerrigan fights her way through the Dominion to get to him. Kerrigan herself notes in a cutscene he's had it coming for all he's done.
Perpetual Frowner: Raynor looks a lot less happy in this one, starting with his first appearance. The only time we see him look happy is the very end.
Power Up Full Color Change: In the beginning of the campaign, Kerrigan and any Zerg she controls are colored orange (same as in Wings of Liberty). After her transformation, they go with a purple color scheme. Not only is this supposed to indicate Kerrigan's newfound power, but also signifies her being truly independent of Amon.
The entire Protoss faction show up for a grand total of three missions early in the campaign and aren't heard from again. On the other hand, they were already pulling out after the events of Wings of Liberty, Kerrigan's plans would be over before they began if Protoss command got wind of them, and the anti-Protoss missions are explicitly about preventing that from happening, making it a Justified Trope from a story aspect.
The Tal'Darim appear in 3 other missions, in the Hybrid arc. Turns out the Tal'Darim are in league with the Hybrid.
The Brood Mother Niadra is a literal example. She's introduced in a mission where you have her conquer an escaping Protoss ship, and then at the end she's separated from Kerrigan and you don't hear from her for the rest of the campaign.
Putting the Band Back Together: The main goal of the Zerg campaign is to rebuild the Swarm from the splintered factions that formed following Wings of Liberty.
Reality Is Unrealistic: So the primal zerg are creatures that consume other creatures' genetic code and mix it with their own. Quite a ridiculous understanding of biology... But have you heard about Bdelloids?
Reliable Traitor: Several zerg either betray Kerrigan, or fully admit that they are planning to betray her if she ever weakens. When asked about it, their reaction is basically "Uh...because we're Zerg? You didn't see this coming?" To her credit, Kerrigan usually does see it coming.
Revenge Before Reason: Even after finding out that a dark god is planning to use the zerg as a weapon in a galaxy-level extinction event, Kerrigan still insists on fighting Mengsk. However, she gives her underlings orders to retreat and prepare for the real enemy if she dies.
Fridge Brilliance: if you're going to have a dark god descending on the galaxy, who do you want in charge of one of the three playable races who can oppose him: an Omnicidal Maniac and former terrorist or his more sensible son and heir? (Of course, none of this is spelled out in-game, so the original trope stands.)
Revision: The Zerg origin story as explained in the StarCraft I manual turns out to be missing a few key details. Yes, the Xel'naga created the Zerg, yes, the Zerg turned on their creators. Except the reason they did so was because the fallen Xel'naga Amon forced a Hive Mind on them, as well as the overriding purpose to consume the protoss specifically. Their biological origins are changed as well, from body-snatcher parasites that developed the ability to mutate into host species (the larva were originally the pure Zerg) to creatures that directly gain mutations by devouring prey. Also, Zerus still has life on it, sporting an Avatar-level of predator-infested man-eating jungle rather than the ash planet it was first described as.
Roaring Rampage of Revenge: Kerrigan's willing to destroy entire planets to get to Mengsk, the man who left her to die in the first StarCraft I. Jim's apparent death after mission 2 as well as Mengsk's subsequent announcement of this doesn't help dissuade her.
Kerrigan: The killing won't stop until Mengsk is dead.
RPG Elements: Kerrigan's in-game unit is conceptually an expansion on Warcraft III's hero units. She gains Experience Points and levels as the game progresses, making her tougher and stronger. Every 10-15 levels, she gets to pick an additional power from a choice of two (three later on).
Screw This, I'm Outta Here!: In the attack on the prison ship, after Mengsk starts a self-destruct sequence, the Dominion forces inside quickly decide there's no point in fighting the zerg anymore. But in a cruel irony, there's no escape, so fighting pointlessly to their deaths is all they can do.
Sequel Difficulty Drop: In general, Heart of the Swarm is much easier than Wings of Liberty — the custom evolutions for the Zerg units make them incredibly powerful, Hatcheries produce up to 9 larvae letting the player get an army out very quickly from nothing, and in most missions there's Kerrigan who has an array of powerful abilities that let her steamroll a lot of opposition on her own. Story-wise, this provides a borderline case of Gameplay and Story Integration — Word of God is that at the end of Brood War Kerrigan was fully capable of crushing Mengsk and the Dominion beneath her heel, she just didn't care to do it. Now she does.
Sequel Hook: Kerrigan creates a broodmother to infest a Protoss ship, and then abandons her. Then the broodmother states her only purpose is to destroy Protoss. So, chances are we'll be hearing from this creature in the Protoss campaign.
Kerrigan and Stukov discuss the United Earth Directorate at some point and agree that they will be back someday.
Single-Biome Planet: Surprisingly averted when it comes to Char. It's always been depicted as a volcanic planet but one mission takes place in a festering acid swamp being used as a breeding ground for banelings. Of course, toxic fumes and acid pools are known to be around volcanically-active areas in real life, so it's likely Blizzard realized they could have more than one biome on a volcanic planet.
Shoot the Shaggy Dog: Intentionally invoked. After all the time, effort, and nearly impossible missions spent de-infesting Kerrigan, one of the first things she does is re-infest herself, and massacre the forces you controlled in the previous campaign. All the stirring heroic speeches, good men lost, and heartwarming moments of brotherhood are all utterly wasted. The effect this trope has on Raynor even becomes a crucial plot point. This trope is triumphantly averted at the end of the game, when Kerrigan clearly demonstrates that she had taken the opportunity to redeem herself and become a hero.
Start of Darkness: We finally learn the Dark Voice's origin. He's actually a Xel'Naga who tried to destroy all life in the universe and recreate it in his image during a fit of pride and jealousy. The other Xel'Naga put him down for it and now that he's been revived he wants to claim vengeance on them. We even get a name for him—Amon.
Stealth-Based Mission: The level "Enemy Within" has you infiltrating a Protoss command ship with a single Zerg Larva that you must hide in steam vents and captive fauna to avoid patrols. It becomes a more standard 'installation' mission after a while though.
Superpower Lottery: Kerrigan practically becomes a PhysicalGod over the course of the game. Guess it makes up for the fact that she will never be a cute redhead again.
Suspiciously Similar Substitute: The Broodmothers fill the role that the Cerebrates once held. Justified, as the Cerebrates created in Brood War weren't meant to survive without an Overmind. The Queen of Blades needed replacements created to extend her control of the Swarm.
Terraforming: When the Xel'Naga started experimenting with the Zerg, Zerus was a volcanic world. By the time of the campaign, it is a lush jungle world with a few volcanic patches.
Kerrigan delivers an iteration of this Stock Phrase to Raynor in the first trailer.
Kerrigan: The girl you remember is dead.
As well, when Kerrigan returns to take control of the Swarm, she repeatedly asserts that she is not the Queen of Blades, as she has only the vaguest memories of that time. However, she eventually comes to embrace the role of their new queen.
Kerrigan, being The Chessmaster that she is, anticipated that she might have to go up against something that could use the Zerg's hive mind against them, and it turns out that she had kept Dehaka as an ace up her sleeve for that very moment. In dialogue with other characters before that particular emission, she even discusses the fact that in the past the Terrans had used the Zerg's hive mind against them (read: psi emitters and the Psi Disrupter). If she'd ignored the possibility that they would try something like that again, she'd be considered Too Dumb to Live.
Video Game Cruelty Potential: You're playing as the Zerg, so this is a given. The Char missions are particularly notable in this regard, as they're the same forces you commanded last game, and you can slaughter them mercilessly.
Ironically Kerrigan is more evil when she looks human. Early on in the game, Kerrigan claims there is "something dark" inside her, representing Amon's influence, which is removed when her primal infestation is complete. Before this infestation, she kills Warfield on Char (though she does honor his last request and lets his men go), and on Kaldir, she slaughters a Protoss research colony that just happened to be in the neighborhood (though they'd have called in the Golden Armada and annihilated her if they got word back); afterwards, she saves Raynor and generally tries to limit the destruction to military targets only, and by the end of the game goes well out of the way to prevent civilian deaths and ensures Valerian will be in place to take over as a new leader to prevent unnecessary chaos. She still does these acts if she gets the primal infestation early, though, indicating that perhaps the real reason for her ruthless actions is that Jim Raynor is acting as something of a Morality Chain (this is especially clear with Warfield, as she kills him only when he hits her Berserk Button by accident), or that (especially in the case of Kaldir) she does these acts only because she is compelled to do so under the circumstances.
Weaponized Offspring: The expansion introduces the Swarm Host unit that spawns short-lived locusts. The Primal Zerg Pack Leader Slivan the Eternal Mother resembles a massive Swarm Host that dumps massive amounts of Banelings on you. In another mission the Brood Mother Niadra spawns several zerglings without the use of a hatchery.
We Have Reserves: The player, naturally, but Mengsk gets in on the action too. Also, this is one of the major advantages of the Swarm over the Primals; the Primals are more powerful individually but the Swarm is numberless.
Now more than even before for the Zerg, as Kerrigan gains several abilities to summon troops for limited time and also one that allows her zerglings to respawn indefinitely.
The Zerg get several possible upgrades that make them even rushier. Zerglings can be upgraded to "swarmlings" that spawn instantly, three at a time, and Kerrigan can learn an automatic spell that revives dead zerglings for free. Corpser roaches spawn roachlings from dead enemies, banelings can be upgraded to be an exploding Asteroids Monster, and the Zerg equivalent to the siege tank is a walking hive that spawns locusts. Two of the missions on Char have Kerrigan totally overwhelming her foes with hundreds of zerglings and banelings.