Storywarp

Storywarp? The soon to be best game ever! The story goes something like this: You fall down a hole in a mountain, discover you're in a monster world, and need to pass through an impassible barrier to get back to the human world. And there's three ways to go about completing this feat: You can attempt a pacifist run, wherein you don't kill anything throughout the entire game. A neutral run, where you kill or don't kill as you please. And a genocide run, where you go out of your way to destroy every monster in your path and hunt ones you miss.

Main story
You're greeted by a cute little flower named Mettaton. The adorable little guy describes how nice it can be in monster land. He then sends some "friendliness glitter" for you to catch and - OH GOD. The son of a bitch turns evil and says that there's only one rule - to kill or be killed. Right before it looks like Mettaton's going to kick your ass, a weird fish in a dress scares him off. I couldn't trust that flower, but I'm sure a fish wearing a dress won't fuck us over.