This is all my art-class class friends' fault.
I think I'm getting a bit obsessed with this game. I told my twin brother about it and he BOUGHT THE GAME when we got home from school on that half-day. I love my bro.
That was last Wednesday.
I got into it a bit before by watching Markiplier start it and then some of the GameGrumps playthrough.
And now I really want to make Sans and Papyrus plushies, and we haven't even finished the pacifist story yet.
I don't want to play genocide mode, everything in that game is too precious to kill.
I DON'T WANT THE FEELS.
But at the same time I do.
NNRRRRRRRRGGGH.
Anyways, if you guys haven't played/watched someone play, I highly recommend doing so.
The writing in the game is hilarious, the music is great, and the fights (or lack of, depending on how you play) can be pretty challenging.
Oh, and all the characters are lovable, and you can either play through the genocide story (where you kill everything), the pacifist story (where you kill nothing), or neutralist (where you do a bit of both).
Also there are a lot of cool/hilarious fan- made things (art, animations, plushies, etc.).
If you like the same sort of things as me (which you probably do, why else would you be reading this?), you'll probably love this game as much as I do.

The animation I linked is a funny GameGrumps animated from Undertale, by the way. Their playthrough has been really good (what I've seen of it so far).