It's an amazing game op (probably my GOTY), but yes the fans can come on a bit strong. Lots of meme'ing, lot of "omg you gotta play this", and holy shit you better have safesearch on if you go googling. Hopefully it doesn't deter too many people from playing the game.
It's true. It is EVERYWHERE. I have 9 and 11 year old girls and they and their friends are obsessed with it. Hell, I recently took them to a museum that had a wall you could put sketches up on and there were a TON of Undertale drawings by kids.