|Next Level A||Together at Last|
|Next Level B||Childish Things|
Insanity is the fourth nightmare in the game Neverending Nightmares. It takes place in what appears to be a Victorian-era psychiatric hospital. The image that represents this nightmare on the Nightmare Select screen is a close-up of a cell door.
The nightmare begins with Thomas Smith waking up inside a padded room with a bed and a barred window. Shortly after getting out of bed, a ruckus of screaming and objects breaking occurs outside the cell. After all the noise dies down, the door of Thomas' cell opens, allowing him to leave.
The nightmare primarily involves Thomas navigating the hospital's numerous hallways and rooms. As the nightmare progresses, the rooms gradually become more bloody and gruesome, with even a few corridors having large piles of dismembered corpses. All of the hallways have cell doors, most of which Thomas can inspect to show the inside of the rooms. Patients roam some of the hallways to make things slightly difficult, and a few corridors also have broken glass on the floor that can be evadable or avoidable.
Near the end of the nightmare, Thomas will be forced to walk on broken glass and alert a nearby patient. Thomas' only option is to enter an occupied cell and then succumb to death by the dweller. When he wakes up after "dying", Thomas finds himself in a psychiatrist's office with Gabrielle Smith sitting at a desk. The two engage in a conversation, revealing that Gabrielle is actually not Thomas' younger sister but an employee of the mental hospital. After they finish talking, Thomas can leave the room and resume his journey. After passing through two more hallways, Thomas will reach the exit and can leave the asylum, which reveals that the building overlooks a large abyss. Thomas can either return inside the hospital or fall into the void, and depending on what he does Thomas will be taken to one of two nightmares; the former action leads to Together at Last, while the latter leads to Childish Things.
- The letters of the left eye chart in the doctor's office spell "EVERYTHING IS A LIE" twice.
- When Thomas enters the second corridor from Block A Security, the door strangely lacks a closing animation. This is the only instance in game where this oddity happens.