The increased throwing power references both Kel's weapon of choice being toy balls he throws at enemies, and his overworld ability in which he can throw balls at faraway switches and objects to activate them.
The increased speed references how Kel is the fastest member of the party, and will often act first in most battles.
The constant spawning of food and the enemy becoming invincible after eating references Hero's status as the healer of the party, and how many of his support skills involve making food for himself or other members of the party.
The fighter being Hero is a reference to how the two share the same name.
The player starting with a flower on their head, along with the stage being Garden of Hope, references Basil's affinity for flowers and plants in general.
The constant appearance of food plus the enemy getting stronger after eating references how Mari can always be found at picnic blankets around the game, and how eating the food offered at her picnics fully heals the party's Heart and Juice.
The three yellow Kirbys represent how the player fights three Lost Sprout Moles in quick succession at the beginning of the game as a way to learn about the emotion system.
The starting conditions of each fighter represent the "Angry", "Sad", and "Happy" status conditions, respectively.
The stage being Spear Pillar references how Space Boyfriend is fought in Otherworld, the OMORI equivalent of space.
The enemy gaining increased attack but lowered defense is a reference to the "Angry" status, which Space Boyfriend inflicts on himself during the fight against him several times.
The enemy having increased move speed and a chance to land critical hits references the "Happy" status, which gives increased speed and an increased critical hit chance, at the cost of attack accuracy. Sweetheart locks herself into this emotional state early on in her fight.
The enemy becoming giant after a while references Pluto's "expanding" in the fight against him.
The enemy gaining increased attack power but reduced speed references how these same stat changes happen to Pluto every time he "expands" in the fight.
The fight taking place on Pictochat represents White Space, where Omori resides when not on an adventure with the party, and the location in which he is fought by Sunny as the final boss of the main route.
The enemy having increased power on their slash/stab attacks references Omori's weapon of choice being a knife that he keeps for the entire game.
The enemy being healed when at high damage multiple times references how Omori can survive a lethal attack at 1 HP during a fight, with the message "OMORI did not succumb." displayed afterwards. This gameplay mechanic is turned around on the player during the fight against Omori, in which Omori will never die no matter how many times the player brings his health to 0, with the first few phases displaying the "OMORI did not succumb." message, before changing to "OMORI will not succumb." after the third time his health is depleted.
The screen darkening as the fight starts references how the fight against SOMETHING IN THE DARK takes place in the dark.
The enemy tending to avoid conflict is a reference to how the fight against SOMETHING IN THE DARK is not an actual fight, and the enemy cannot be hurt. The fight is normally a scripted event that ends when Sunny remembers and uses a certain skill.
The sticky floor is a reference to SOMETHING IN THE WALLS taking the form of a giant spider, and using webs to inhibit Sunny's movement.
The enemy tending to avoid conflict is a reference to how the fight against SOMETHING IN THE WALLS is not an actual fight, and the enemy cannot be hurt. The fight is normally a scripted event that ends when Sunny remembers and uses a certain skill.
The player being unable to swim is a reference to how SOMETHING IN THE WATER represents Sunny's fear of drowning after falling into a lake as a child and nearly drowning before he was saved by his sister Mari. The fight against SOMETHING IN THE WATER takes place in the same lake, when Sunny has to face his fear and jump in to save Basil from drowning after Aubrey accidentally pushes him into the lake.
The enemy tending to avoid conflict is a reference to how the fight against SOMETHING IN THE WATER is not an actual fight, and the enemy cannot be hurt. The fight is normally a scripted event that ends when Sunny remembers and uses a certain skill.
•The enemy has super armor and is hard to launch or make flinch •The enemy becomes temporarily invincible after eating •The enemy has increased defense after a little while
The enemy having super armor and increased defense but lowered speed is a reference to the "Sad" status, which grants increased defense and causes damage to be split between depleating Heart and Juice, at the cost of decreased speed. Doughie and Biscuit inflict it on themselves during their fight, and eventually move all the way up to the third tier of the emotion, "Miserable", which renders them functionally invincible until their Juice is fully drained, as all damage done to them at this stage will instead be directed entirely towards reducing their Juice.
The player starting at 999% references how in his "battle" against the player, Life Jam Guy instantly KOs your entire party besides Omori in order to give the player Life Jam and have them use it to revive their fallen party.
The item tidal wave references the Life Jam that Life Jam Guy gives the player at the beginning of his fight.
The enemy preferring not to move references how Life Jam Guy does not attack the player, and spends any turn he gets talking about the benefits of Life Jam instead.
The enemy being invincible references how Life Jam Guy cannot be killed during his fight, or even take damage at all. Any attacks against him do nothing, and the fight ends only when the player has revived all their fallen party members.
•Defeat the main fighter to win •The enemy has super armor and is hard to launch or make flinch •The enemy has increased attack power after a little while
The endless army of K. Rools references the Gator Guards Mr. Jawsum constantly calls on during his fight to protect him.
Bowser preferring not to move reference how Mr. Jawsum does not attack on his own during his fight; rather, he has his Gator Guards attack for him, and he cannot be hurt unless there are no Gator Guards protecting him.
The enemy gaining increased attack power but decreased defense is a reference to the "Angry" status, which Mr. Jawsum will frequently inflict on himself and all Gator Guards still present in the fight.
The enemy having vastly powered-up stats references Perfectheart's status as a superboss in 'OMORI'. She can only be fought on the Hikikomori route, and is so powerful it is practically required to go into the fight at max level and with the best gear possible.
The enemy can also heal when at high damage, which references how the first time Perfectheart's health is depleated in her fight, she will fully heal herself and then spend the rest of the fight attacking at full force.
The battle taking place on Skyworld is a reference to how the battle against Perfectheart takes place in a cloudy sky, which appears to be Heaven.
Trivia
Omori's Spirit battle is the only Spirit battle to make use of the "Health Recovery" rule multiple times; this is achieved by having the event trigger at different damage values (90%, 100%, and 110% respectively).
Aubrey is represented by Inkling in both fights featuring her, but in The Hooligans Spirit battle, she is represented by a pink Inkling instead of a purple one; this is in reference to her dyeing her hair pink in the real world, while Headspace features her with purple hair.
Perfectheart's Spirit battle is tailor-made to be as difficult as possible. The Peach CPU is set to level 9, her stat boosts are set to the highest possible value, and her base stats as a Spirit opponent are set to the highest value a Spirit can have as an opponent. Her stats as an equippable Spirit (when said stats are maxed out) are also the highest value possible.