At the end of every "world", there is a Meal Ticket chest at the campfire scene, and Shovel Knight dreams of Shield Knight. Shield Knight and the Meal Ticket chest have the same red/gold palette, so of course it reminds him of her.
I always wondered why the annoyingly difficult Specter Knight, who's level is not only full of instant-death traps but is also obnoxious to fight, is parted with the relatively easy King Knight in "world" 1. That was until I realized he is based around death, being like a Grim Reaper of sorts. His stage and especially his fight will most likely kill you a lot (especially on your first play-through) because his motif revolves around it.
Why is Shovel Knight so smart, unpredictable and reacts to your attacks? Because Shovel Knight's battle style is based on how a player would react to a boss' attack. Remember that Shovel Knight is the default and original player character, so naturally he'd fight like one too.
If you're like most players, you very likely beat Shovel of Hope on at least one file before starting Plague of Shadows. Plague Knight's story is Shovel Knight's New Game+. Which provides an alternative explanation for his behavior: A player that took the moral high road in their first playthrough will be inclined to take the Jerkass low road in at least one subsequent replay. Plague Knight being the perspective character at the time gives the player a handy excuse to assume Shovel Knight's Jerkass moments are non-canon, rather than what the player themselves would've done in that particular replay.
At the end of the final boss fight, Shovel Knight says that he knows a shortcut out of the Tower of Fate. Of course he does: he had to use it when it was sealed all that time ago.
During the fight with the Enchantress, she can damage the floor you are on, but can also restore it. Could Shield Knight be trying to help Shovel Knight even when possessed?
This does not seem to apply with Plague of Shadows, until you either finish the battle or just think of it a little more: She's holding back because she still sees a chance to be stopped or saved by Plague Knight.
When battling her with Specter Knight, it's part of her gambit to snuff out Specter Knight's free will and secure him as her eighth and final knight.
The battle with King Knight, similarly to Specter Knight, may have been a deliberate gambit to recruit him. Letting him win would add some credence to her talking up King Knight's abilities to seduce him to her side.
Polar Knight's stage seems to have a lot of bombs hidden in walls or blocks of snow. This makes perfect sense; after all, Shovel Knight and Polar Knight know each other! Polar Knight probably knew that one of the best tactics to use against Shovel Knight would be to booby-trap anything that he could dig through.
Not to mention, what is Polar's weapon of choice again? A Snow Shovel.
Going by this logic, it's not hard to see why he's pretty much the only boss to actively, purposefully block your pogoes.
When Plague Knight defeats the Enchantress, she doesn't revert to Shield Knight. Since the game implies that Shovel Knight and Plague Knight's stories take place concurrently, with only a few possible, player controlled deviations (Plague Knight hiring Baz, him bothering to pick up the paper he finds worthless for Percy, etc.) it stands to reason she decided to quit while she was ahead with Plague Knight and just give him her essence and end the fight rather then risk her amulet being damaged. She's thus still in fighting shape for Shovel Knight's battle.
In Plague of Shadows, why does the Troupple King serve as Plague Knight's Armor Upgrade Shop instead of providing consumable ichor potions like he does for Shovel Knight? First, he knows that Plague Knight is an alchemist, and likely has the whole health restoration thing covered (which he does with his Health Tonics.) Second, Plague Knight wears robes, not armor, so dying the cloth with magical fluid would be a lot more effective and useful than trying to stick armor onto the outfit and weigh Plague Knight down.
Mona reveals that Plague Knight is capable of making gold himself out of sawdust and mouse skulls, yet Plague Knight still has to use treasure from levels to pay for upgrades. Why doesn't he use this ability at all? Talking to Chester for the first time has him mention he's suspicious of accepting gold from an alchemist, so likely alchemists being capable of making gold is something of common knowledge, and thus Plague Knight probably couldn't use that gold regardless with his poor reputation in the area, especially if the seller is someone like Chester.
This principle also applies to the only other people besides Mona (whom is also an alchemist) Plague Knight can buy things from. Troupple King outright states he only grants his ichors to noble cases, so Plague Knight certainly wouldn't want to risk incurring his anger with fake gold, and this also would apply to the Magicist (one of his colleagues) as well, in this case to keep her trust.
Technically though, someone could possibly use crafted gold like normal gold as long as the other party doesn't know it is. Of course, while Plague Knight being outright known as an alchemist couldn't, someone like Mona, whom is able to stay outright in the open as no one is aware she is, could. Remember the gold prize she gives out for her mini-game? That's very likely crafted gold.
And why Shovel Knight can use this crafted gold just fine? Because he doesn't know it is crafted and people would trust him more than Plague Knight and thus accept it.
When the essences start crashing on Plague Knight and Mona tries to get to him, the Plague of Shadows sprite actually appears on Plague Knight's place for a split second in a flash, signifying that it's Plague Knight's battle against himself. After that, it appears behind Plague Knight, and then the fight starts. Then when that boss gets defeated, the Corrupted Essence manifests. It becomes even more brilliant. The track name for the final boss is titled The Battle Within.
Plague Knight can beat the Plague of Shadows by standing still for 40 seconds. This seems strange, but it makes sense; Plague Knight spent his entire campaign fighting other knights for their Essences, covering up his insecurities with retorts and flippancy. Standing still, something that goes against everything Plague Knight is, shows to the Plague of Shadows that Plague Knight has the strength to face his inner self.
In hindsight, Mona having a connection to Plague Knight is subtlety hinted at in Shovel of Hope, even if the two are never seen together at all in the campaign. While the biggest hint is the fact her mini-game uses the same beakers used by the Alchemeiser mini-boss of the Explodatorium, it's also implied by of all things by the interface. To explain, characters have their names colored, and Mona's color is a dark green in Shovel of Hope. What's notable about it is it's the exact same color as Plague Knight's. Also, Croaker's pun for her involves calling her a 'vial woman'. Knowing Mona is an alchemist (which doesn't have a good reputation judging by some dialogue in Plague of Shadows) on top of working with Plague Knight (whom isn't exactly the nicest person ever to put lightly) as his research partner, the pun borders on If Only You Knew. The same colored text is especially more noticeable as Croaker says the pun involving Mona right after Plague Knight's.
In Plague of Shadows, there's something odd with the room where the Phase Locket is found. All the other rooms have no enemies in the area immediately around the chest where the relics are found. The Phase Locket had three Boneclangs right before the chest. Those were guards Specter Knight had assigned to guard the Phase Locket.
Shovel Knight is classified as a Wandering Traveler in Plague of Shadows not just because of his love for adventure, but also because of how frequently he finds himself in other games, just as the Wandering Travelers do.
While playing through Plague of Shadows, I realized the title while referring to the penultimate final boss, also had another subtle meaning. Plague Knight's campaign takes place at the same time as Shovel of Hope, and thus his adventure is in the shadows of the main campaign.
From what we see for Specter Knight's gameplay, we see that he has a "Will" gauge instead of Health, even though they're functionally the same thing. Why is this? Specter Knight is already dead and can presumably resurrect after each death, so "Will" is more like gauging his motivation to continue rather than his actual health.
In Shield Knight's description, her con is 'occasional recklessness'. This isn't apparent in Shovel of Hope, but in Specter of TormentDonovan battles Shield Knight alone, and it's implied by this and how Shovel Knight dreams of her falling she rushed ahead of him to get to the amulet, which leads to her being possessed.
Most of the bosses in Specter of Torment (and by extension King of Cards) have one or two extra tactics that they don't use in Shovel of Hope or Plague of Shadows. It's odd that they would just ditch something that makes them better in a fight, but there are explanations for a few of them:
Black Knight obviously wouldn't want Terrorpin fighting for a while after his injuries.
Tinker Knight stopped using the Mobile Gear because Plague Knight stole it from him. This also explains why he constantly falls over while fighting Shovel Knight and Plague Knight: he's not as used to moving in battle without the Mobile Gear. Additionally, the reason the Tinker Tank is considerably easier for the other playable characters is because Specter Knight wrecked it up during his fight with Tinker Knight and it's still being repaired.
Also, why Shovel Knight isn't able to use the leverage and rocket features of the Mobile Gear is because it was also damaged during the fight and Tinker Knight was unable to find time to fully repair it.
Treasure Knight most likely decided that shooting gold coins at enemies was a waste of money. Especially now that he has a lot more minions to pay, and is no longer close enough to the surface to drain his treasure room.
In the ending, we see most of Propeller Knight's fleet take off from the Flying Machine, meaning they wouldn't be around to help him fight.
King Knight doesn't break the floor anymore either because it's sturdier now and he can't, or he was already behind on renovations before and doesn't want to. As for the other moves using the Propeller Rats and throwing cards; by the time of Specter of Torment, King Knight and Specter Knight had previously battled at least twice, thus King Knight knows what his opponent is capable of and has some new tactics to use against him. By comparison, by the time Shovel Knight and Plague Knight come to confront him in their respective campaigns, he's become used to living comfortably on the king's throne, and may be holding back against them out of cockiness.
Phantom Striker is holding back against Shovel Knight and Plague Knight as he wishes to test their resolve rather than kill them, even stating as such to them during the encounter - hence why he never uses both the lightning strike and the circling orbs attacks.
Mole Knight's excavation isn't very far along when he's recruited, while in Shovel Knight's story he's much deeper into the earth, thus the switch to explosive blocks instead of slime blocks.
Plague Knight doesn't use his clone technique because Shovel Knight dropped by the Explodatorium completely unexpectedly and he had no time to set it up. The same applies to Shovel Knight's version of the boss rush. He's able to use the technique in his fight in King of Cards because Percy buys him enough time to prepare.
The Troupple King being willing to help Plague Knight makes a lot more sense after the ending of Specter of Torment. His acolytes were both minions of The Enchantress before they converted to his cause, so another defector wouldn't be that surprising.
The female acolyte remaining in the Armor Outpost after Plague Knight takes over makes more sense, too. It's not that she's too wacky and obsessed with spreading her message to recognize danger, it's because Missy probably recognized Plague Knight and his goons from the Tower of Fate.
Some of the changes to the OST in Specter of Torment make sense with the general theme of the area, compared to how they sound in the other two games.
The Lichyard's new song is perhaps one of the most upbeat and joyous, which seems a little odd considering it's Specter Knight's stomping grounds, one would think it would be the most somber remix. But this makes sense when you consider the town's still there; the tragedy has yet to occur and the song sounds lively.
King Knight's takeover of Pridemoor Keep is still in progress when you go set him straight, with the walls still made out of stone instead of having been turned into solid gold, so the remains of the old monarchy are still there, making the song sound more jubilant and regal than after the pretender's takeover of the throne, when the song is more serious.
Going from this, according to the Bard's comment concerning "In the Halls of the Usurper" in Shovel of Hope, the song is actually based on Pridemoor's regal fanfare. The song in Specter of Torment ("In the Halls of the King") is thus the original arrangement of the song.
Specter Knight's "From The Shadows" is a slow and gloomy rendition of Shovel Knight's more energetic and triumphant "Strike The Earth!". Shovel Knight's run through the Plain of Passage is the start of his quest to vanquish the Order of No Quarter with renewed vigor after his 10-Minute Retirement. Specter Knight's is the start of his quest to create the Order of No Quarter as part of his servitude to the Enchantress.
Shovel Knight leaving the Order of No Quarter hanging without bothering to help them is a rather dickish move for such a noble hero - except they're the Order of No Quarter. They are knights who don't give mercy, and by the rules of chivalry, that means they don't deserve it either.
Alternatively, since Plague of Shadows is told from Plague Knight's point of view, Plague Knight is trying to smear Shovel Knight's reputation by claiming Shovel Knight struck him in the back and left the Order hanging. Why? Because Plague Knight doesn't want to admit that Shovel Knight defeated him.
Mona's dance after defeating King Knight and Specter Knight is a waltz. On inspection, there's an interesting detail; her dance has her left hand at around her waist, when during an actual waltz, the left hand should be around the shoulder level of the partner. Then one remembers Plague Knight reaches about Mona's waist, so if Mona was dancing with him in mind, it would be in the correct position. Which could explain why she was unusually flustered being discovered: she felt embarrassed thinking her crush was watching her dance to an imaginary him.
The Phase Locket presumably gained the "phasing" power after Specter Knight purified Reize. It originally could bring someone back to life, but now it merely contains a ghost of its former power.
In Specter of Torment, we clearly see Plague Knight use the Tracer and Cascade Powders, as well as the Impact Fuse (all which need to be purchased from Mona). Yet why does he start Plague of Shadows with only the basic bombs? According to a comment Plague Knight makes, Percy once launched him straight into the ocean, leaving his bombs waterlogged during a time when he couldn't afford replacements. That could be why Plague Knight starts with sub-par equipment during his campaign and why he has to pay Mona for the rest.
This idea could also explain why he doesn't have the Vat Arcana at the start of the game: Plague Knight lost it in the same incident he lost most of his bomb supply in. Now, remember Chester offers the Vat Arcana in the Iron Whale, which is IN the ocean.
Why is Plague Knight so much smaller when you play as him? If you find his room in the explodatorium, you can look in his closet, where you can see what appears to be his much larger outfit that he wears as a boss. He may be using trickery to make himself appear larger in order to be more intimidating. Alternatively, since he is something of an Unreliable Narrator, his smaller size in Plague of Shadows may just be reflective of how he views himself, as smaller and less impressive than he really is.
All four characters' final bosses are a corruption of the thing they wanted.
Shovel Knight returns from retirement to find Shield Knight, and is constantly haunted by his dreams of failing to catch the falling Shield Knight, indicated to be the last time he saw her alive. His final boss is the possessor that stole Shield Knight's body and used it as a puppet.
Plague Knight sought to improve himself because he didn't feel adequate enough for Mona to love him, going on his journey to create a potion that could grant that desire. His final boss is a corrupted, monstrous reflection of himself, indicating that his greatest obstacle to what he wanted was himself. One of the boss's attacks uses explosives in the shape of Mona, reflecting how Plague Knight trying to make himself worthy made her believe he was using her.
Specter Knight sought to return to life, at first seemingly for selfish reasons, but actually to fulfill a promise he made to his friend Luan to protect Reize in his place. His final boss is a possessed Reize, who represents both his promise to Luan and some part his guilt for causing Luan's death. He ultimately is able to free Reize by using the locket's power, fulfilling his promise and atoning for Luan's death, but dooms himself under the Enchantress in the process.
King Knight's at first seems to fit with his desire to be king, except only one of the 3 components is a king; the Birder explicitly says he is no king beforehand, and it is the Troupple Acolyte, not the Troupple King that becomes a part of it. Because it's implied King Knight truly sought the love, admiration and loyalty that came with being a King, and thus faces a corrupted amalgam of his own biggest supporters. The boss' Clipped-Wing Angel form being without a crown and exposing its true face could reflect how King Knight, pursuing what he believes he wants (the title of king), ultimately loses everything in the end by siding with the Enchantress.
Why is King Knight so dead set on becoming a true king? Because he was born and raised in a small, squalid hut swarming with rats and he yearned for something better.
For someone so obsessed with Royalty and ostentatious posturing, it's ironic that King knight's Animal Motif is a rat (hardly a majestic of dignified animal). Yet considering that he came from poverty, it may serve as a motivator; if lowly vermin can become regal and resplendent, then so can he.
King Knight using "You wouldn't leave us to hang here, would you!?" towards Shovel Knight makes a lot more sense after King of Cards. The ending of that campaign implies that he regrets, if only slightly, his decision to abandon all of his family, friends, and supporters to join The Enchantress and become a "real" king. With that in mind, he's likely saying this to Shovel Knight because it worked well on him when King Pridemoor said it.
Some of the places you get unique cards are reflective of the characters they represent.
Shovel Knight and Shield Knight are found in the Tower of Fate's Joustus House in two chests, side by side. Likewise, you find the Enchantress card in the secret passageway in a hidden room containing Shield Knight's helmet.
Plague Knight's card is not acquired from him, but from Mona, making him an unusual exception as he's a potential Joustus opponent. It's implied he doesn't have his own card because Mona took it from him for winning and considering her own feelings toward him, she took his card on purpose.
The Luan and Reize are only obtained from winning against Specter Knight, whom as Donovan, was close to both of them. Luan is already dead and Reize doesn't appear in King of Cards. For the latter case, this might have been on purpose on Specter Knight's part to keep Reize away from the Tower of Fate and the Enchantress.
King Knight's card and his mother's can be found in the hidden room in the Homestead. However, while King Knight's Mom's card is found in a visible treasure chest, King Knight's card is hidden by a wall in the same room. It serves as a subtle foreshadowing of King Knight alienating her with his choice to side with the Enchantress to become a real king.
Showdown's character selection having both Shield Knight and Reize and their corrupted/possessed selves makes sense when the mirror's breaking causes a splitting up of the two sides.
King Knight not only usurped King Pridemoor's castle but also stole his battle style — though, from a meta-perspective, it's the reverse. Pridemoor's boss fight uses King Knight's strategies, only better suited for the true king's titanic battle armor. The key similarities include an immobilizing ground-pound followed by swiping the opponent with his scepter, pausing then charging quickly across the room, and calling upon an outside force to rain projectiles to provide pressure. Regarding the latter, King Pridemoor's variant summons Plume and Beaky, while King Knight's summons the Horns of Heralding.
After finishing King of Cards, I felt that unlike the character-driven stories I received from Plague of Shadows and Specter of Torment, this was a step down. Then I realized that unlike Mona in Shadows and Reize in Torment, King Knight's mom, the only person King Knight truly cares for, is a bit character with no appearance in any other story, and above all, the person King Knight cares for most is himself. There was minimal character development and interaction in this story because that's who King Knight is.
Another point about King of Cards is how King Knight turns on his allies on knocks them all into a pit. While it serves as a nice contrast to when him and the rest of the Order are put in the same situation after the Boss Rush, there is also a gameplay related reason as well. Note how Shovel Knights main attack is a swing of his shovel, which could be inferred as using the blade to turn the winch holding everyone. King Knights main form of attack, however, is a Foe-Tossing Charge. Given how the winch breaks apart in this instance, it provides subtle foreshadowing in King Knights fate.
Specter Knight seems to lengthen his cloak (and therefore granting himself his Shovel of Hope moveset) when he gives in to his defeatism. This happens during two instances before the main game: in Specter of Torment's ending after lamenting about being forced into the Order, and before that, during his final bout with King Knight in King of Cards. For the latter, it seems he Turns Red only because he realizes the strength of the usurper's convictions is too great. He's still obligated to continue fighting, but phase two indicates that Specter knows he's running out of options.
By Shovel of Hope, it's possible he learned how to exploit this outward defeatism to his advantage. By starting the fight off with this simpler battle style, he's granting Shovel Knight one accessible step closer to the Tower of Fate. This could be Specter Knight's revenge that Red implies after collecting every red skull in Specter of Torment.
Shovel Knight's pre-fight dialogue with Propeller Knight is oddly standoffish for the Blue Burrower, especially considering how he tries to talk down the other two bosses in the third section of the map. However, the Flying Machine is the closest stage to the Tower of Fate on the map, and Propeller Knight is guarding the third and last lock to the tower itself. The Flying Machine is probably meant as the "canonical" last Order of No Quarter stage, which means Shovel Knight is just itching to get back to the Tower of Fate at this point, and he's not going to waste any time trying to reason with Propeller Knight when his goal is so, so close.
During King of Cards, from the two times you face Specter Knight, he seems to fight more akin to his moveset in Specter of Torment and he's notably exhausted afterwards. Only during the second one dues he go One-Winged Angel and fight like he does in Shovel of Hope or Plague of Shadows. Why is this? Well, King of Cards takes place before Specter of Torment. It's implied in the credits that Specter Knight just started serving the Enchantress since he hasn't gotten the rest of the Order of No Quarter together. As such, it's plausible that Specter Knight was just newly resurrected and hasn't gotten used to his powers or any potential undead pains he has.
Shovel Knight and Black Knight obviously have a history as friends. How betrayed must Black Knight feel to actively try to hurt, maybe even kill, someone he once considered a friend?
At the end of each "world", when Shovel Knight dreams about Shield Knight falling, he catches her...and then wakes up. But it's not a Catapult Nightmare. He's used to it. How many times has he been having the same dream since she disappeared, succeeding at saving her only to wake up and she's still gone?
It IS a Catapult Nightmare. You (Shovel Knight) wake up by jumping. Crosses over into Fridge Brilliance because he's not only showing how startled he is to wake up in such a way, but the reason he jumps at all is that he's still trying to catch Shield Knight.
The Lich Yard was a village before the Order of No Quarter was formed. The background in the first part of the stage even looks like one - with what seems to be a church or a town hall and some houses, even an entrance sign at the beginning of the stage! After Specter Knight's attack, what was once a village is now a graveyard.
Actually, it was confirmed that it used to be a village. One of the NPCs mentioned she lived in her village before Specter Knight attacked, and that she narrowly escaped it. The epilogue for Specter of Torment actually shows the attack. At least it's a fair bit more merciful than the Enchantress' treatment of the Armor Outpost, and the Phantom Striker ensures that most of the inhabitants get out safely...
The appearance of both the Plague of Shadows and the Corrupted Essence is already terrifying, and the Corrupted Essence is basically Plague Knight's idealized self, so what could have happened to him and Mona if he wasn't able to defeat the boss?
Despite the implication that both the final bosses of Plague of Shadows are not actually real, but are a mental manifestation of Plague Knight created by the Serum Supernus, it doesn't take away any of the horror of the situation since if Plague Knight failed to defeat the boss (aka remains unconscious), that means he isn't able to complete the final distillation to stabilize the potion. Said potion is unstable and dangerous, meaning both have a high chance of actually dying from it.
Does Reize know his father died by his "uncle's" hand? Does he know his dad is dead, period?
It seems that he knows his father is gone, but not that it was because of Donovan... and he seems to recognize him after the final battle.
Specter Knight is entirely reliant on the Enchantress' magic to continue his Undeath after he sacrifices the locket to save Reize. With her taken down by Shovel Knight, what happens to him then? Shovel Knight's ending acts like maybe he'll be self-sufficient, but whose to say his magic won't run out? Or worse, if the fact that he's still alive means the Enchantress may not be entirely destroyed...
There might be some Fridge Brilliance connected with this, if with a bit of WMG. When making Donovan into her Specter Knight, the Enchantress says "When Eight Knights kneel before me, it will gain the power to restore life". You can get the Phase Locket pretty early on in both Shovel Knight's campaign, the only one besides Specter to have the Phase Locket long enough in the story. The locket regained its full power when Specter Knight said he'd be the Eighth Knight, meaning that potentially a case of Exact Words could be in play. Think about it: What does Shovel Knight do before he faces the Enchantress? Defeat Eight Knights, whether in their home territories or in the Boss Rush right before her room. Technically speaking, the "make eight knights kneel before me" could be read as "defeat eight knights before you return to me". For all we know, Shovel Knight might've fulfilled the Locket's conditions once more and Specter Knight still might have a chance of being fully restored.
Considering that Donovan and Luan lived in the Lich Yard prior to Donovan's death, Specter Knight is essentially stationed in his former home that he himself helped raze to the ground.
Why King Knight is a Warm-Up Boss after King of Cards showed how capable and how powerful he can actually be? The answer lies in the end... Either King Knight feels empty and broken about losing his friends, and especially the affection of his mother, he's basically lost all motivation for fighting. Or he simply got so lazy he barely cares about putting up a good fight anymore and feels even if he fails his "subjects", the rest of the Order of No Quarter, should finish the job, after all a King should command, not fight. Or both.
Showdown reveals another reason: being out of shape from eating the food from the parties no one attends and sitting on the throne all the time. So by the time Shovel Knight faces him, King Knight's largely an out of shape, rather dis-motivated man. However not quite enough that he wouldn't try to fight with what he had left.
An odd observation is that even if you save them, King Knight still curses Shovel Knight, complaining about the loss of his lands, possessions and luxury. When you play King of Cards, this suddenly makes sense. He betrayed everyone in order to get the Kingship he wanted. Nobody wants to associate with him. The castle, luxury, fiefdoms and chandeliers were likely the only things he had left, and now he doesn't even have them.