Remember the "Cow Level," the secret level in Diablo 2? Blizzard's hack-and-slash role-playing game (RPG) Diablo 3 has apparently got one for itself too.
Uncovered by an enterprising player, the secret level in Diablo 3 is called "Whimsyshire." Once you enter the level, you'll get a feat of strength, a banner and a sigil. It's a land of magic full of bright colors and rainbows, where jolly fantasy characters like unicorns, smiling clouds, ponies and teddy bears wander freely. But yes, you can bash them all up at will.
Zerofire, the player who discovered the secret level, wrote in a Blizzard forum post that "Whimsyshire" can be played "as many times as you want" and for finding it, you will get a "Land of Killer Unicorns" achievement.
IGN noted that "Whimsyshire" could be a reference to early criticisms of the colorful graphics of Diablo 3. On the other hand, it could also be a reference to the Diablo 2 "Cow Level" that was itself a response to the rumors of a Secret Cow Level in the first Diablo game.
In the forum post, Zerofire offered a way to unlock the secret world of "Whimsyshire." If you are impatient and just can't resist cheating to find out what the mystical land of lush greenery has in store for you to explore, follow the instructions posted here.