Irisu Syndrome
You think LSD gave you the creeps? Play this game.
So without giving away spoilers, it's a freeware Japanese puzzle game starring a cute bunny girl, Irisu Kyouko. There are shapes of various colors falling down. Use your mouse to launch white blocks to make the shapes collide with another of the same color to score points and regain health.
As you progress through the game gaining more and more points, you can unlock various scenes involving three university students out on a camping trip. Of note is an old story one of them tells about a witch in the area.
An updated version titled Irisu Syndrome Metsu has been released, containing the original game with updated graphics and music as well as a continuation of the story.
Here's the
link for Irisu Syndrome Metsu. It's in Japanese but you can manage.
If you want an English version, here's the
link for that. Although, it's not the updated version. Either way, you'll have a blast playing this.
Gameplay Screenshot (I can't give videos because it will spoil the game for you)
If you want to enjoy the game to the fullest extent, don't google the game for information. Trust me, the links I gave are safe. Googling it will result in a shame for your play through.
All I can say is Good Luck.