vessel

interacting with the broken body in chapter 2 after inserting the loadeddisk (but before the spamton neo fight) gains a reaction that implies kris is frustrated it didn’t work.

during spamton’s first encounter, he has some (seemingly) throwaway dialog about pressing F1 for help. if you press F1 during this fight or during the spamton neo fight, a spamton angel will appear to heal you, but only once.

in deltarune, undyne has no idea who alphys is. meanwhile in undertale the pair are raging lesbians.

the swan boat in chapter 2 may be a reference to the pedalos from off. interestingly enough, while the pedalos actually resemble ducks, another npc named sugar has a swan symbol on the floor of her room and official art exists of her riding a swan.

noelle is the first character in the game to notice that kris is acting strange. talking to her at the end of chapter 1 prompts dialog where she wonders why they’re so talkative, and if you visit rudy in the hospital before this, more dialog plays where she’s even further confused.

the everyman from undertale makes several appearances in deltarune. first seen as a replacement for the duck heads in jevil’s carousel attack, then seen in the graffiti near the apartments in the light world, and then seen in chapter 2’s enemy poppup’s pop-up ad.

kris’ title upon entering chapter 5’s aborted weird route is “shattered rose,” with a description that alludes to a deeper secret but also reads like a steven universe reference.

the thornring is revealed to be a single thorn in the light world during the chapter 4 weird route, which included a now-removed cutscene of a rose falling apart. this implies the thorn is a rose thorn. additionally, kris is often associated with roses.

during the 2022 spamton sweepstakes, an arg ran in the background on deltarune’s website. this rabbit hole includes faux blogposts written by noelle, a mini-game, as well as other little weird tidbits.

in chapter 1 you can visit the lake and befriend onionsan, who cryptically tells kris they want to share a secret with them that only a friend can hear. they are then last seen in chapter 2 telling kris they want to explore the depths of the lake. in chapter 5, a new npc (resembling a secret npc from undertale) sells takoyaki that tastes like onions. also in chapter 5, the weird route’s pivotal moment takes place at the lake, further emphasizing it’s weird importance. onionsan is likely foreshadowing for the weird route chapter 5 scene.

this dialogue you can get in the chapter 3 egg room mirrors npcs from across both deltarune and undertale, all of whom have monochromatic copies