Alien invasions are perfect video game fodder. They provide a fantastic backdrop for amazing heroism and allow the use of neat sci-fi weapons and gadgets that might otherwise seem out of place. Perhaps the enticing aspect of this scenario is the underdog factor. Except for a few rare occasions, humanity is almost always the ones who are being overwhelmed by the advanced alien weapons and powers. It's much more exciting when humans can come up with a way to blast aliens to pieces. Everyone loves an underdog victory, and 0 Day Attack on Earth is a game built entirely on this concept. It doesn't have much of a plot, but it focuses entirely on what makes those sorts of adventures exciting: pilots in inferior machines using their skills to overcome a seemingly unstoppable alien foe.