In episode 4 a peach coloured pug is shot by Skip after revealing itself as a cerebro slug to him, this is shown comedically and isn’t described in really any detail.
Not strictly gaslighting, but similar enough: in episode 10 it's revealed that a player character has had a memory erased from their mind by someone they once trusted.
Two human NPCs die in a fire caused by a vehicle crash in episode 5. A static image shows their bodies (miniatures with a cartoonist aesthetic) in the middle of the fire. A player character is also set on fire at the same time, but it does not kill them.
In episode 4, the player characters non-violently kidnap an NPC with the intention of protecting them from the antagonists.
Also in episode 4, the party kidnaps a dog.
In episode 10, the party kidnaps another NPC. They think they're rescuing her, but have misunderstood the situation. They also slap her and threaten her with a gun at one point.
In episode 15, a player character is drugged and taken hostage.
In episode 4, a dog is mind-controlled by a parasite.
EPISODE 2 SPOILERS
A human character becomes mind- controlled by a parasite. This is described in-depth from the perspective of the parasite, who is a player character. It's comedic in tone.
There's some further in-depth description of the parasite probing the human's mind in episode 10.
From episode 10 onwards the party meet various NPC antagonists who are being controlled by a brain parasite, including some of the player characters' loved ones.
Episode 15 features some particularly gory description of parasites entering people's brains, in the scene after Brennan says "cut to Barry and Skip". This scene also features a moment in which a mind-controlled character is briefly allowed to regain control of their body, and is clearly very upset and distressed by what's been happening to them.
In episode 16, the brain slug PC takes over a new host.
When Norman kisses the person in a gas mask in episode 11, he "vomits" a brain slug into their body; this is described verbally and accompanied by vomit sound effects. You can avoid it by skipping ahead a minute or so when Brennan says "you see something horrifying happen".
A similar thing happens again in episode 15 around the 42-minute mark, and again at (approximately) 45:30, 48mins, 50:45, 52:50, 53:10, 1:32:50 and 1:32:55.
The show takes place in an ableist setting, and a disabled character experiences workplace discrimination and the pressures of a hypercapitalist healthcare system (including the threat of having their cyber-prosthetics violently repossessed if they fail to pay their debts). This is despicted in a way that satirises ableist and capitalist systems in the modern-day US.