The recently released Metal Gear Solid V: Ground Zeroes has been receiving a lot of positive feedback, but the game also has a bit of controversy surrounding it. Ground Zeroes, which is currently priced at twenty dollars for digital copies and thirty dollars for physical copies, only has about two hours of gameplay in it; even less if you know what you're doing and completely disregard the five side missions. Some believe that the game is nothing more than an overpriced demo of the real game, Metal Gear Solid V: The Phantom Pain, which won't be released until early next year. Others view it as a necessary prologue to hook gamers into the next generation of Metal Gear and whet their appetites until the full game is ready to launch. Either way, Ground Zeroes is selling like hot cakes, and there are a ton of MGS fans who are more than happy to fish out any amount of dollars needed to play a brand new entry in the franchise. If Ground Zeroes continues its rise up the sales charts, it may lead to other developers creating and selling their own "prologue levels" of upcoming games. 2014 and 2015 are going to be big years for gaming, and here are twelve upcoming titles that, if given great prologue levels, could sell as much as or even greater than MGS V.