Undertale effect 

A phenomenon in which a video game, movie, or other piece of media that was never intended to be perfect gets hyped up as such by its fan community, causing those diving in to have far too lofty expectations. This is followed first by disappointment when it fails to be perfect, then by backlash against the fans who hyped it up - and, inevitably, the game itself. This results in a cycle where the "fans" and "haters" become distinct groups who get increasingly vocal and vicious with each other, debates over its contents become less rational and more personal, until eventually all legitimate discussion about the original subject becomes impossible.

Popularized by the 2015 video game Undertale, as of this writing it is still extremely difficult to bring up the game in any context without getting attacked - either by diehard fans who refuse to recognize that the game has flaws, or diehard haters who refuse to recognize that the game has strengths.

I once brought up Undertale in a conversation. I got told to kill myself, and then the conversation veered off-course into bickering between the fans and the haters. That's the Undertale effect for you.

Undertale effect by JonBon3311 December 19, 2016

Undertale effect 

A process in which an indie project (either show or game) grows so big to the point where people start hating it due to how big it is.

“It has barely been a week and Digital Circus is already suffering from the Undertale effect!”

Undertale effect by Redsparrow09 October 21, 2023

Undertale Effect 

When a video game becomes popularly hated due to its fandom as opposed to the game itself. Part of cringe culture. Often results in a hatewagon.

"Let's play Fortnite!"
"Eugh, why Fortnite? That game sucks. The community is filled with whining kids."
"Didn't you have the same reaction to Undertale? It was a good game but the community ruined it? Isn't most Fortnite hate just another Undertale effect?"

Undertale Effect by JTIG22 August 30, 2018

The Undertale Effect 

The Undertale Effect is a cycle that any form of entertainment media community can fall into.
Essentially, the community will COMPLETELY over rate the show/game/book/movie/etc., and defend it as if it is their life. The community will almost always turn the lovable, funny characters into cringe, and rapidly spread throughout the internet.
The strange thing is that the only outlets to suffer from The Undertale Effect are those from something that by itself is great. The show/video game/movie/etc. is usually great, and has many redeeming qualities but it is overshadowed by the atrocious and toxic fanbase.
Quite obviously, this is based off of the worst case of this ever happening yet - Undertale. I won't get into it now, but the smallest peek into the (dead now) community will tell you.
This has infamously happened to: Steven Universe, Five Nights at Freddy's, Minecraft, and unfortunately even Rick and Morty.

Right now, Rick and Morty has fallen into the Undertale Effect. Just look at Musical.ly, the fan art, the cancerous reddit copypasta, etc.

The Undertale Effect by That_One_Dodgy_boi October 22, 2017

The Undertale Effect 

A term used when a video game or television show becomes unbearable to play/watch because of its fanbase.

"It sucks how badly the Undertale Effect ruined Rick and Morty."

The Undertale Effect by PhantomBird529 September 17, 2017

The Undertale effect 

Once something popular releases, the community and any content made about it WILL degrade and become worse overtime.

"hey have you noticed the twitter community on welcome home keeps getting worse?"
"That, my good friend is the undertale effect happening in practice"

The Undertale effect by AmnesiaPen May 6, 2023

The Undertale Effect 

By listening to undertale ost's your vrt increases by 100% causing you to get good kovaak's scores. Often people confuse it with 𝓪𝓲𝓶𝓫𝓸𝓽*.

*𝓪𝓲𝓶𝓫𝓸𝓽- a bot that aims.

Me: oh you got a good score on arc dodge switch?
My friend: yeah i used the undertale effect.
Me: oh that makes sense now

The Undertale Effect by Saltcult February 9, 2021