Samus and Bowser Jr. give off the Bomb ability because they both drop explosives in Super Smash Bros. (although Samus has this as a regular move in her series).
Mr. Game & Watch has the Circus ability possibly because he's a Fighting Clown, or as a reference to his juggle attack from Ball (1980). Further completing the latter reference, the remake of Ball from the Europe/Australia-only title Game Boy Gallery took place in a Circus.
Villager and the other Animal Crossing characters give the Leaf ability as a reference to the leaf motif of the games.
Yoshi giving Whip may not make much since at first, but when you consider that Yoshi's tongue is used much like one...
Wii Fit Trainer gives off Doctor because she works with health like a doctor.
In Xenoblade, Shulk gets the power to see into the future, via the Monado. That's a psychic thing, hence his amiibo giving ESP.
In accordance with the game's theme of robots and computers, the game implements a subtle instance of recursion. The first letters of each area's names combine to spell P-R-O-G-R-A-M, which is used to refer to the Mother Computer, Star Dream. The last world, where Kirby fights Star Dream, is titled "Mind in the Program".
President Haltmann's Interface Screw attack has him plaster the screen with 100-thousand bills with his face on them. In his 2.0 form, they're 50-thousand bills with Susie's face on them. He may be using them as the rich man's version of a Face on a Milk Carton, hoping that eventually someone who has seen her in the money could find his daughter.
It may seem egotistical and cheap of Haltmann to value the currency with Susie's image at half his own face. However, this might actually have been a smart move on Haltmann's part if you think he has some grain of economic sense: Valuing Susie's bills at lesser denominations would mean there can be more bills with her on them circulating without causing an inflation.
President Haltmann's battle theme is #86 on the game's Sound Test. He's 86'd.
You also have to wait for 86 seconds to enter the secret HAL room in the level 6-5.
The Haltmann Works Co's varied branches of development and interests — the robotics and cloning, in particular — make a little more sense when we consider Haltmann's true motivations: What would someone with access to advanced technology do when they are trying to bring back someone they lost? Make a clone or a robotic replacement, perhaps? (That is, until he started to work on his wish-granting supercomputer AI, which suggests these ventures failed...)
Kirby cannot use amiibo when he is using the Robobot Armor, but he can use it when he's fighting Star Dream after the Robobot Armor copies the Halberd. At first, it may sound a bit strange that this Robobot form will allow amiibo while the other forms will not, but it makes sense when you think about it. The Robobot itself has a relatively small cockpit, while the Halberd is a big enough ship to have a "changing room" for your amiibo.
Of all of the bosses for Star Dream to duplicate, why Dark Matter Blade and Queen Sectonia? Because they're both swordspeople. They're fighting Meta Knight.
Not only that, they're both from games that Meta Knight did not physically appear in, and therefore have not been defeated by him before.
On a similar note, it is mentioned, right before Galacta Knight is summoned, that Haltmann forbade Star Dream from using the program it uses to summon him. Most people presume this is because of Galacta Knight, but look at the name of the program: "Space-Time Transport program". What reason would Haltmann have to prohibit use of such a program? Maybe a freak accident that sent someone he cared for who-knows-where?
The final two lines of the Japanese description for the final heart form of Star Dream Soul OS basically says that "As a being that doesn't dream or eat, it's no match for Kirby!" This only seems to be a simple motivational speech...then someone proved that this is much more literal than possibly intended.
In every other Kirby game, the Copy Ability descriptions have a lot of personality to them, like someone was embellishing each ability or like Kirby himself was describing them. In Robobot, the descriptions are more cut and dry than anything, and seem more detached from the setting. Which makes sense, seeing that Dream Land's been turned into a roboticized version of itself and is devoid of its usual flair. But when Kirby runs around in the Robobot Armor, the descriptions suddenly sound way more life-like, as if he's taking back some of that lost personality by obtaining the mech.
At first, you wonder why Dedede Clone is the boss of Rhythm Route. But then you remember the music-themed hazards in the actual level, that all rely on the timing of the background song. Sounds like a decent Call-Back to Dedede's Drum Dash.
On that note, the hazard timing in Rhythm Route must be the reason why, in this Kirby game, the music pauses when you pause the game in the non-boss areas, while a lot of other games just let it play.
Several stages have food-themed structures in the background. Juicebox-shaped apartment buildings, soda can-shaped water towers, blender-shaped oil rigs, candy cane patterned faucets, and even underwater cities in giant milk bottles. What do these all have in common? They're all foods commonly made or packaged in factories!
The game doesn't homage Mega Man X just from the Robobot Armor, or how Kirby can copy powers. There's how, in the end of the standard playthrough, Star Dream calculates Kirby's power as "nearly infinite", just as how people have called X having limitless potential.
Why Haltmann Works Company is such a success? His name has "HAL" in it. It even shows by one of Star Dream's attacks shooting the letters H, A, and L.
Along with robots, the game also uses the theme of screws. From how some puzzles have you uncork giant screws, or how the "factory bases" are shaped like screws (as Kirby runs spirals around them to access their doors), or how Clanky Woods has drills for legs and, later, use a screw-like mechanism to transform the stage around him. The kicker, however, is how the Star Dream has a screw's top design, Kirby's Robobot Armor in the final battle using his screwdriver as a drill to drill through the Star Dream and Access Ark, and how Kirby's powers are described as "nearly infinite". Conclusion: This game has quite some influence from Tengen Toppa Gurren Lagann.
Why have a giant screwdriver-drill as the last weapon you use in the game? Because the final boss Star Dream is really a Galactic Nova, which resembles nothing so much as a gigantic pocket watch. Now, what's a good way to ruin one of those? Over-winding it, which can damage or destroy delicately assembled internal components.
Why is the Poison ability so similar to the Water ability from Return to Dream Land? It may represent the idea of the Haltmann Works Company's mechanization of the environment, polluting the water and making it poisonous.
And as for why Water itself isn't in the game, water will short out any electronic device, making it a crippling Logical Weakness to every mechanical hazard in the game and necessitating that it be absent to avoid curb-stomping the Haltmann Works Company.
Kirby being concerned for Susie after seeing her get knocked out by Star Dream is commonly seen as a bit of his compassionate, forgiving nature shining through. While Susie hasn't exactly been nice to him throughout the game, her theft of Star Dream's program controller came just as Haltmann was about to use it to eradicate the natives of Planet Popstar. Intentionally or otherwise, Susie managed to save Kirby's life with what she did.
Star Dream Soul OS might seem like all other soul bosses at first glance, but in reality, its not really a soul boss at all. By the time its fought directly, the only soul component of it, Haltmann, has been deleted. At this point, Star Dream is just a machine imitating what a Soul boss would act like and not entirely getting it. Its name specifies that its a Soul Operating System, not Star Dream Soul or Soul of Star Dream. It attempts to teleport randomly like the other Soul bosses would, but its teleportation isnt very random at all. It follows a rapid, set path, never moves vertically, and only shows variation when it moves back and forth right before it attacks. When it splits in two, it cannot do the rain of paint trick because its not a soul; it can only recombine and cause explosions. However, it still tries to do the rain of paint with missiles of the same colors. Just like the teleportation, the missiles follow a predictable path around the battle arena, unlike the paint that falls at random. The only recurring Soul attack it seems to have down pat is the four-way cutter attack, which in all honesty wouldnt be very hard to replicate.
When Star Dream Soul OS's health is fully depleted in its final phase, the heart returns to the center of the stage and pulses exactly 12 times before being defeated for good (the red shockwaves being released during the tenth, eleventh, and twelfth pulses.) Considering Kirby was fighting the heart of a clockwork star, it would be only natural that its last-resort attack would count to 12.
Amusingly enough, Kirby: Planet Robobot can be considered the most literal title in the series due to its Final Boss. Star Dream's second form is a fusion of it and the Access Ark, the latter of which is the size of a planet. In other words, Kirby fights a literal Planet Robobot at the end of the game.
The reason why Star Dream Soul OS has metallic plating around it is because Haltmann may have modified the heart to have combat capabilities, something that the Galactic Nova Nucleus is shown to be devoid of.
For some reason, the Spanish translations turned Star Dream into a program rather than a computer. However, this is not really a mistake: combining the first letter of each level now spells out 'proceso', or process, which is what programs start and stop. Additionally, his Soul form also got a Dub Name Change: Sueño Estelar.exe, and in order to start a program, the most basic thing you need is an executable file.
The Luke, I Am Your Father trope has been done an awful lot, hasn't it? But unlike most other instances of this trope, Susie never realizes that President Haltmann is her father, and he never realizes she's his daughter. And now he'll never know, considering the fact that his soul has been wiped from his supercomputer. Should there ever come a time when she finally does realize the truth, how do you think she would feel about it? She likely would have to live the rest of her life knowing not only what happened to her father, but also that she tried to betray her own father. For all the terrible things Susie's done, it's hard to wish such a fate upon even someone like her, let alone a child.
During the scene before the fight with Star Dream, in the Japanese version, Susie states that she wanted to "wake him up with tears in his eyes" (in other words, make him come to his senses) and Word of God says that Susie's most treasured trinket is a golden hairclip with "H" on it.
And to top all that trauma off, an opportunity finally comes for you to put a stop to your father/boss's plans, make a killer profit, and knock some sense into him while you're at it, all while doing away with that pesky "perfect computer" of his. You decide to try and take it, only to inadvertently unleash a nihilistic superpower upon the universe that's bent on eradicating all forms of life, which absorbs your father's body and soul and eventually deletes his consciousness from existence and forces you to turn to the aforementioned native for help in stopping it. In the end, Susie's left with nothing but her hairclip and mech suit, and she has nowhere safe to return to (at least that we know about) after she departs from Planet Popstar.
In the final part of the battle with Star Dream Soul OS, when you're destroying the pillars, you can faintly hear what is unmistakably Haltmann's voice crying in pain every time one of them goes down. This stops once the heart starts to attack you. Around this time, the bio changes to saying that President Haltmann was deleted. The supercomputer didn't erase Haltmann, you did.
When Star Dream Soul OS's Heart is finally destroyed, the grey metal parts of it break off, leaving only a reddish-pink heart like the one the original NOVA had. Then, that heart breaks in half and disintegrates, while crying in pain in a slowed-down version of Haltmann's voice. It's up in the air what significance any of this has to the main story, but it can't be good.
Deleting something from a computer system doesn't destroy it permanently, it just removes it from the computer's directory, marking the space it occupies as empty. Until the computer writes something else to that space, the data still exists on the device, and can be recovered with sufficient skill. Physically destroying the memory banks, on the other hand...
When Meta Knight is mechanised, it seems that he can't do anything to prevent himself from attacking Kirby. And when it is mentioned that the Haltmann Works Company could make a mass-produced production line from him, you have to think... would Meta Knight feel himself being endlessly reproduced and mechanised to do the company's bidding? And if Kirby never freed him...
How on earth did Haltmann get a sample of Dark-flippin'-Matter!? And if he was ever able to get one in the first place... does that mean they're still out there?
Not sure if this fits, but I can kind of see Haltmann's bill-spraying attack as potentially Fridge Horror: He's using 100 thousand and 50 thousand bills, when the highest values normally used by bills are typically around one hundred or one thousand. And he uses a metric crapton of them in the attacks, like what you'd normally expect to see if you loot all of the cashier drawers in a brand name store for bills (and potentially even more). This kind of suggests that the economy of Haltmann's place of origin is severely inflated to the point where they had to start mass-printing bills with denominations that high. What usually happens to society when inflation skyrockets like that?