Undertale

Undertale is a video game that was published and popular in the year 2015. Considered an instant hit to many, Undertale went on to be nominated for multiple awards, such as GotY (Game of the Year), not long after its explosion in popularity. Many fans claim that Undertale has original characters, dialogue, humor, gameplay, and more.

Genocide route
The player starts out as a little human child by the name of Frisk (as Chara is the one they name) who wakes up in a dark area of the Underworld alone after falling into Mount Ebott. After seconds'-worth of traveling to the right, they meet Flowey, a sentient flower whose face can make all these weird shapes depending on his mood. Flowey, at first, appears to mean no harm as he teaches the human how to battle in the game by offering him coke in the form of small, white, spinning pills doing what was scratched out and trying to fuck the human up with said coke pills. If the child is enough of a Dumbass to fall for the little photosynthesizer's trick, Flowey gets trolly and straight-up tells the child that they are a dumbass before getting fireball'd by Toriel, an anthropomorphic cow-looking goat lady who barely ever uses this fireball move again. Flowey rees as he gets launched off-screen and won't be seen again for a little while.

Toriel mistakes the human child for her own after showing them how to do puzzles in the Underworld. These puzzles are so easy, it's almost like Toriel isn't needed to solve them. After Toriel successfully abducts the child, she promises them goods that they never receive, not even in the endgame. After getting bored of Toriel's house and book about snails, the human, being the little miscreant they are, leaves the house, only to be stopped from going far by Toriel who warns the child about King Asgore Dreemurr. Not giving a singular fuck, the human child tries to continue towards the castle, but Toriel is still in their way. They decide to fight and kill the goat mother, allowing them to continue on their journey.

Fanbase
Undertale is known for having a Loony Fanbase who is untameable, even by the forces of God himself. It's spawned a seemingly infinite pit of fanfics, fan videos and art, and furry rule 34. This is enough reason for many people to hate Undertale without actually playing the game or even seeing someone play it.