in act 3 part 2, around the nine minute mark, a character tries (and fails) to commit suicide by swimming into a turbine. the attempt is 9:05, after one character says "surprise attack, gordon!" skip to 9:12 or 9:22 to completely avoid it.
no, but someone dies while being crushed by a self closing door (not graphically), and people talk briefly about what it would be like to be crushed by a hydraulic press
there are two characters that are commonly interpreted as autistic. one is called a freak in act 1 part 1, which doesn’t happen again. the other is frequently demonized, but he’s also the villain.
no, but there is a gun that shoots fingernails/toenails attached to someone’s arm. the loss of his fingernails/toenails does not seem to harm the character
no characters are, but the twitch chat is blurred out at one point because of argument about one of the voice actors, who is transgender (she’s quite awesome! if you can, check out her streams. @hollow_tones on twitch)
during the end fight, the villains model becomes distorted in various ways, but it’s not realistic. there are also several npcs with creatures attracted to their heads; and at one point an unimportant npc grows larger.
one autistic-coded character is infantilized & called a freak once. another character commonly interpreted as autistic is called a freak, insane, and shamed by the main character for his monotone speech and difficulty focusing.
a character is injected with drugs in act 1, but the needle isn’t shown. there is a fight in act 3 part 2 in which the npcs being fought are all holding needles, but they’re quite hard to see and it’s never mentioned.
the person playing the main character had a panic attack off-camera (not an anxiety attack, but. y’know.), and a few times during act 3 it is apparent he is dealing with the aftermath of said panic attack. however, it is never explicitly said.
no character is explicitly stated to be mentally ill, but it is heavily implied for one specific character. however, almost all characters are violent at least once.
there are cockroaches squished in scenes that take place in a vent & a scene centered around moths flying by a light. also, again, alien creatures that resemble bugs
characters are often grabbed by the neck by aliens, and shows signs of choking. there are several scenes where characters are underwater, and can not breathe. characters are generally out of breaths after fights, but this is particularly present in act 3 part 2, because the person playing the main character had a panic attack and is dealing with the aftermath.
one of the major plot points of the series, that takes place at the end of act 3 part 1, is that an arm is cut off. you can hear people yelling about it/pain noises/a knife being taken out of a sheath, but the screen is black during that bit.
no one is explicitly said to have cancer, but there are characters who are exposed to a lot of radiation and cancer is talked about as a thing for them to be worried about developing.
the character who’s viewpoint the series is from, sometimes struggles to leave the water due to ladders in video games being sucky sometimes, and he’s pushed back in to the water (only once & by accident, i think)
there are the lines “oh, he’s injecting me with drugs!” and “the drugs are taking effect!” but it’s never followed up on. also, in the uncut streams there’s talk of morphine being administered for medical reasons
in act 3 part 1 around the 22 minute mark one character states the year the series was made in an ominous voice. in the uncut streams the twitch chat is sometimes addressed but in the videos the viewers are never talked to. at least two characters become aware they are in a video game.