A main character is a high schooler and is implied to have a bad home life, or perhaps is even homeless. It's mostly subtextual and there's no abandonment shown onscreen.
You could also make an argument that the Knight created a great deal of characters and left? All of those characters are presumed adults, though.
A main character who was bullied pretty actively by another main character gets thrown into a situation, in which these two become friends. It's implied the bully had a bad home life and was just playing the role they thought they had to play, and it sounds like there was no actual fighting involved, people just assumed they were evil because they look scary. There is physical violence shown between the two, however.
A hidden route has you essentially gaslight and manipulate a character into 'becoming stronger' and killing for you. It is played purely for horror, as the character in question reacts realistically to your emotional abuse and coercion. It's implied that, by the end of Ch. 2, the character is traumatized enough to see violence as a default option. That said, this route is extremely easy to avoid, and extremely easy to get out of if you're on it.
The alternate route in chapter 2 involves you manipulating a girl into committing genocide, one of the victims of which being a close friend of hers, and gaslighting her as she suppresses all her killings, stuggles to remember what happens during battles and whether or not the events in the dark world were a dream, resulting in a breakdown at the end of the chapter when confronted with the fact that everything was real. It’s very disturbing on a level arguably more than the genocide route in Undertale. The requirements in order to trigger this route are super specific though, there’s no way in hell you’ll trigger this accidentally, or even intentionally without help from a guide, so you can very easily avoid this route if it disturbs you.
chapter 2's antagonist is frequently seen with a glass of battery acid; the acid is implied to have the same effects as alcohol and she is shown to be drunk/tipsy after drinking it in several scenes (the scenes are not optional)
DELTARUNE CH2 SPOILERS //
In a specific route, it is heavily implied that Berdly (a bird) is either braindead or in a comatose in the real world due to the player getting Noelle to perform the SNOWGRAVE spell against him in the dark world.
You can kill a debatably dragon-like character, though it is entirely optional and it really doesn't look like a dragon without stretching the definition a bit.
Kris is slammed against lockers and threatened by Susie. Susie also tends towards violence against monsters in the early game combat, but becomes less hostile over time.
Near the end of Chapter 2, two scenes exist featuring multiple characters being both tied to and gripped by giant hands, unable to break free. In one instance, they are threatened with crushing. The scenes are relatively brief, but not skippable.
A main character repeatedly threatens to eat other characters, and even nearly puts one character's head in her mouth at the start. She never actually carries out these threats.
The acid thing is a popular headcanon, and is only sort of implied in game, the character mentions burning in acid but he's a deeply unreliable narrator
Like Undertale, some of the monster designs are surreal, such as a character with a mouth in their stomach that comes complete with a tail-like tongue. However, they tend not to evoke violence or gore in any way.
One of the enemies you encounter are based on lego blocks, you have the option to rearrange them to spare them, but failure in doing so would place their legs where their head should be and viceversa. It's played comically and It shouldn't be of issue
there's a few little scenes where it happens;
the more major one surrounds a certain character in a very specific route. if you do this route, you can freeze the character and in the real world they will become unconscious (or possibly dead, we aren't sure). you can't really do it accidentally though!
there are also a few other small ones. in chapter 1, there's an unconscious enemy that later wakes up after being beaten by another character. in chapter 2 a character gets turned to stone, whether that counts or not is up to you - they turn out fine as well!
i think that's all!!
Minor spoilers for hidden content:
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On the hidden alternate route, you can equip a ring made of thorns to a young girl. The ring's description states that the "wearer takes damage from pain", and said character's hit points will then drain rapidly in battle.
Attempting to equip it to any of the other characters has them outright refer to it as a torture device and refuse.
Edit: In chapter 1, there's eye imagery everywhere at the start. Some of these drawings have black goo coming from them, but it's all art.
A character, when manipulated and forced to cast a spell, 's eyes lose their pupils. It's virtually impossible to do this accidentally, though. There's also a character whose eyes are never shown until the end of Chapter 1, in which they glint red. It's probably just their natural eye color though, and it's all very cartoonish.
The MC has a sword which can be used to attack others, and later brings out a knife they have. It's played for laughs next chapter, after it's revealed they just ate some pie, hut they later sneak out and (presumably) slash their mom's tires. No actual stabbing is shown.
It's possible for the protagonist to "die" when their HP hits 0. Nothing is shown and you can immediately load your saved game.
Another major character's status can become ambiguous through a hidden route. It's not possible to trigger the route accidentally.
Attacking enemies in Chapter 1 will simply cause them to flee, however during a secret route in Chapter 2 multiple characters (including one major character) are able to be frozen solid, and are implied to be dead.
A main character's sister disappeared at some point. It's likely she will end up being found again, but characters refer to her in the hopeless way you do when you accept someone as dead.
There is a quite frightening scene at the end of chapter 1 (when kris gets out of bed and starts limping). It could possibly be considered a jumpscare.
A single mannequin outside the Addison's shopfront in Chapter 2, being sold as an equippable armor item that does not affect the player character's appearance.
Hi, deltarune fan here. This is incorrect. The existence of cops in a piece of media doesnt equal copaganda. Also, the cops have been shown thus far as reckless and completely incompetent.
One hidden character is imprisoned and several are in cages in the basement of the castle. Later, another major character is seen imprisoned. Some minor characters are in the jail in the police station in town.
Not sure if it counts, but Chapter 2 has the antag use electrical plugs wires to control people. SPOILERS FOR REST If you don't loosen the wires in the Queen boss, this will result in the electricity damaging a minor character's arm.
In chapter 2, there are computer virus and computer anti-virus enemies. Jokes relating to health and real viruses are at play, and when doing a certain ACT, susie holds a very large syringe.
*MAJOR SPOILERS* a character is seen ripping their own heart/soul out at the very end of the game, but we aren't sure what this means yet and it is possible that it could or could not be self harm
It's unspecified what kind of illness they have, and it doesn't feel super stigmatized, but it could be triggering for someone. The two characters it applies to seem prone to derealization, and they're depicted somewhat sympathetically.
So it's neither explicit nor stated, but as someone who deals with both derealization and depersonalization I'd like to say I relate to Kris and their conflict so unreasonably much. Personally I find the game is incredibly touching and sincere in its handling of these themes even if it's never made direct and I feel like they hang over much of what the game is really trying to get at, but in terms of acknowledging they're there it's difficult to avoid the allegorical angle once you notice it.
No, but there are some upsetting implications from certain lines: After an arcade machine sequence choosing the option "perish" in the choice prompt makes Kris apparently say it very enthusiastically. There's also a line during a battle with an enemy who wants Kris to give up their SOUL that seems to imply the only reason they gave that they wouldn't agree is out of fear of where that would leave their friends afterwards. Very sad headspace for our main character overall.
If you beat a difficult, optional boss battle in Chapter 2, the main character is implied to be having a panic attack or meltdown afterwards. You don't see it, per se, but you see how other characters react.
in one of the optional battles the main character is said to have goosebumps and starts screaming if they say no when asked if they are ok. debatable whether this an anxiety attack but still worth mentioning!
There is a scene very near the beginning where the playable character is backed into a corner, then slammed into a locker by a more physically imposing character.
one of the overarching plot points has to do with the player possessing the main character, and a few characters are implied to know the player exists.
Kris canonically uses they/them pronouns; in-game, everyone uses the right pronouns at all times and Kris' gender is never commented on. However, much like Undertale, this is a point of contention in fandom spaces, so be cautious.
Kris, who is canonically non-binary, can die in the same way any RPG protagonist can, however none of these possible deaths are related to homophobia or transphobia whatsoever.
The only human character in the cast is of a color which is somewhat difficult to interpret. Imagine orangish-LEGO vibes and you'll get the general image.
There are some religious references - one family of monsters is Christmas-themed, there is a church (not able to be entered) and a priest (who can be spoken to) and some references to heaven and angels.
A character with a vocal tic mentions hell on occasion. there's a "heaven" that is implied to be bad and requiring banishment, possibly being hell. Some character mention the occult, and there's a chance you as a player are a demon. We don't really know yet.
Ralsei looks similar and has a similar name to Kris's brother Asriel, and is implied to have a crush on Kris. However, there is no information on whether Kris and Ralsei are actually related.
in chapter 2, a character will deliver the line "It Means Tity" after prompting a dialogue referring to her "bosom". the dialogue is comical and entirely optional.
A large aspect of one of the bosses is that they were evicted and forced to live in garbage, and a main character, though perhaps to a less confirmed extent, seems to have questionable stability in their home life.
At the start of chapter 2 once you leave the school a track that is entirely composed of car horns (that occasionally honk to the theme of certain characters) plays, also, during multiple scenes with queen her car makes some screeching noises
There's a very comical scene where you control a car hitting cartoon cars that make a tiny sound and fly (implied to be harmlessly) off screen, your car also explodes at one point, but all 3 characters inside leave first, and it's the stock explosion you've seen throughout the game
Chapter 2 has many crosswalks that they must traverse, pressing buttons to stop the active traffic. Getting hit by a car harmlessly returns you to the nearest bit of sidewalk, but you do indeed get hit by a car