Star Wars: The Force Unleashed is a behind-the scenes story that bridges the gap between the "Revenge of the Sith" and "A New Hope" movies. It tells the story of Starkiller, Darth Vader's secret apprentice and personal assassin. Vader took Starkiller as a boy and raised him in secret, away from the prying eyes of the Emperor, to be his secret weapon, both against the remaining Jedi in the Galaxy and against the Emperor himself when the time came. The Force Unleashed begins with Starkiller being sent on a final series of "tests" of his ability by Vader to prove that the boy is ready to help his master kill the Emperor and ascend the throne. Before long, Starkiller's tests turn into something far more important, and his seemingly normal adventures end up shaping the events in the original "Star Wars" trilogy.
The idea of a "shadow" who wanders through history is fairly neat, but what Starkiller does ends up so completely over-the-top and ridiculous that it feels less like an interesting but forgotten part of history and more like someone's fan fiction character was interjected into a video game. He does so much and so blatantly influences the Star Wars plot in front of so many of the movie characters that it is basically impossible to believe that this guy was a forgotten part of history instead of a major icon. It's really quite silly, and while the idea of forgotten characters isn't exactly new to the Star Wars video games, The Force Unleashed handles it much more ham-handedly than the Knights of the Old Republic and Jedi Knight franchises.