This game changed my life.
Undertale came out in 2015, when I was in 6th grade. I was a social outcast, and I found it difficult to talk to people. I saw Jacksepticeye uploaded a new video, so I decided to click on it and watch it. It was his first Undertale video.
I loved the humor, I could tell the game was written by a good person with a great sense of humor. I found that I resonate with some of the characters in ways I had never before. I wanted the game.
So, after begging my parents to let me buy the game, I bought it, and, as you can see, I haven't put as much time into it as I would have liked to, but I'm a senior in high school now.
(I still haven't finished Genocide.)
After seeing everything I believe there is to see in this game, I can comfortably say that it is one of, if not the best game I have ever played, if not ever made. The characters are unique, funny, and the dialogue is amazingly written. The way the characters interact with each other is very entertaining as well. These characters do not feel prewritten, they feel alive.
This is why the Genocide ending is so much more scary and sad. These characters that you've gotten to know so well, these friends you've made, are all dead. And even when you reset after a Genocide ending, and do a Pacifist ending, it's still implied that those characters did not survive.
However, the Pacifist ending is very nice. If you enjoy feelgood movies, you will enjoy that ending (although if you're reading this I assume you've already seen the ending).
Anyway, the game is good. But if you take anything away from this review, just remember. The game is good. Stay away from the fandom. The fandom is not good.
TL;DR: Good game, very funny. Bad fandom, not funny.