Complete Monster: Jack Shepard is a cop who moonlights as the Nightingale Killer, a Serial Killer who targets nurses, strangling them to death and stealing their jewelry. By 1969, he had already murdered three women this way, and when John Sullivan, a cop in 1999, prevents his father Frank from dying in 1969 note using a ham radio that can communicate with the past, he also inadvertently causes his mother, a nurse, to save Jack Shepard's life, allowing his murder spree to continue. By 1999 in the new timeline, Jack had murdered 7 more women, including John's mother, who had saved his life, and Jack's own loving mother. Frank and John attempt to stop the murders in the past, but Jack catches on, beating up Frank and stealing his driver's license to place on his latest victim and frame Frank for the murders. Near the end of the film, he attacks both John and Frank "simultaneously" in 1969 and 1999, and after handcuffing Frank, attempts to rape his wife. When Frank frees himself and aims a shotgun at Jack, he takes a young John hostage, threatening to snap the kid's neck.
Hilarious in Hindsight: The villain's name is Jack Shepard. The actor who plays him would have a brief appearance on the show ("Eggtown"); Elizabeth Mitchell, who plays John's mother, played Juliet.
In Amplitude: "M-80" and "I Am Hated", for their incredibly fast strings of repeated notes, and Rockit (2.002 Remix) and Out The Box for their incredibly complex patterns, depending on which portion of the game you're better at.