The virtual reality attraction, which essentially focuses on a story line about a possessed patient named "Katie" running wild in a hospital, consists of strapping parkgoers into a chair before they are given VR goggles.
If the game becomes too intense for them, customers can press the "panic button."
The attraction was originally called "FearVR: 5150," with 5150 referring to the state code involving an involuntary psychiatric hold.
Mental health advocates speaking out included Ron Thomas, the father of homeless man Kelly Thomas, who had schizophrenia and died in a violent confrontation with Fullerton police in 2011.
Ron Thomas said the attraction stigmatized mental illness.
"You get in there and get the virtual reality set on, you know you're in an insane asylum, and that this Katie, this patient, is loose and is going to do bad things to you. It's wrong," he said. "The mentally ill are people. They're human beings. They're suffering. They have illnesses, and we have to do something to help them - not demonize them. Not to continue the stigma of mental illness."
One person who took to social media was Kay Warren, wife of pastor and author Rick Warren, who lost his son to mental illness.
After receiving backlash from several mental health advocates and "loyal fans," park officials issued a statement saying the attraction has been removed.
The statement read: "California's Great America is proud of its popular annual Halloween Haunt event. For nine years we have delivered unique and immersive haunted experiences to our fans and loyal guests. Our evening attractions are designed to be edgy, and are aimed at an adult-only audience. Over the past week we have heard from a number of people expressing their concern that one of our temporary, Halloween attractions - FearVR - is hurtful to those who suffer from mental illnesses. Contrary to some traditional and social media accounts, the attraction's story and presentation were never intended to portray mental illness. As it is impossible to address both concerns and misconceptions in the Halloween timeframe, at this time we have decided to close the attraction."
After the announcement, Rick Warren tweeted his appreciation for the park's response.
I commend #KnottsBerryFarm for closing a ride that stereotyped & stigmatized mental illness.Thankyou Knott's for your sensitivity— Rick Warren (@RickWarren) September 28, 2016
Cedar Fair, the company that owns Knott's Berry Farm, also shut down the attraction at two of its other theme parks, one in Santa Clara and one in Toronto.