6. Catherine Atlus
Out of the absurd entries on this list, Catherine Atlus takes the whole cake on featuring a kooky, off-the-wall, bizzaro storyline. To begin with the game's official genre has been coined to be a puzzle-platformer psychological horror adventure video game (what?). The general premise of Catherine's storyline is a man named Vincent debates whether to marry his girlfriend Katherine of five years. Vincent shares his woes with his friends at the local bar called, "The Stray Sheep," where he meets a beautiful woman named Catherine and begins an affair with her. That's when the nightmares begin. The game is split by the mostly cinematic sequences that happen during the day and the nightmare puzzle games that happen at night. During the day, like most visual novels, the player mainly watches anime sequences making choices from time to time. However, at night, Vincent must attempt to climb towers and all his friends in The Stray Sheep have become, um, well, sheep. Catherine Atlus is another game infamous for its adult themed videos depicting the relationship between Vincent and the Catherine's. With me so far? Okay, because this is where things get really friggin' odd. Like many pseudo RPG's Catherine Atlus features multiple endings depending on the actions you take in the game. Just in case you, the reader, care this next part contains spoilers. At the end of the game you learn that the bartender, a dubious man named Thomas "Chops" Mutton (owner of The Stray Sheep, get it) has created the nightmare hell Vincent's life has become. Catherine is Mutton's associate and she is a succubus who eventually kills the men she seduces. Mutton does this so that the long-term girlfriends that these men are not marrying (Katherine) can be single again "for the good of the species." Once introduced to Catherine these men then must play the arcade games Mutton keeps in his bar, which will plant subliminal memories in their heads that can transport them to the nightmare world while they are sleeping. Makes sense to me. Depending on how you play Vincent may actually wind up marrying the demoness Catherine and overthrowing her father Nergal so that he can become the Lord of the Underworld and inherit an entire harem of succubae. Or Vincent may refuse the love of both Katherine's, in which case Mutton tells you he's sorry for causing you stress and gives you money to wager on a wrestling match that you will lose. Or Vincent may take the money offered by Mutton at the end of the game to pursue his lifelong passion of space tourism. What. The. &*%$?