Every gamer loves a challenge; it's in our DNA. Most games these days are made solely for consumerism; titles created for the average player who can run out and nab the latest release, before then taking it home and completing it with varying degrees of simplicity. Whether it be regenerative health, copious save points throughout or purchasable DLC's that turn the game into a cake walk, the industry wants it's players to succeed and be happy about it, so they'll run back out and buy the next game when it's released. This level of people-pleasing hasn't always existed in the realm of video games though, far from it in fact, and there are still studios who refuse to follow the established formula. Such an ideology has resulted in the kinds of games that turn challenging scenarios into downright brutality, testing the highest resolve of their players while sending them into an endless pits of frustration and game restarts. While finishing these 15 video games is achievable, the developers certainly did their best to make sure you lose every inch of your sanity - and voice box - in the process, leaving behind a catastrophic trail of destroyed controllers, keyboards, monitors and consoles in your wake. Ready to revive some repressed memories? Press start...