I spent the last week or so playing the game, and finished out all the trophies for it yesterday, including the "all endings" trophy. There are basically 7 endings, and 21 (going from memory, so I could be wrong at the exact number) epilogues that you can see, depending on how you play. Here are some highlights:
Warning: Spoiler! (Click to show)
- If Shaun dies but Ethan lives, Ethan kills himself. If he doesn't get with Madison, he shoots himself in the head in his apartment. If he is with Madison, he shoots himself in front of her, at Shaun's grave. If he was in jail when Shaun died, he hangs himself in his cell.
- If Norman is alive, but gives up on the case, he retires from the FBI, to go back to the "real world." He leaves ARI behind.
- If everyone but Madison dies, and Madison saves Shaun, she has to battle Shelby in an extended and thrilling fight above the docks. She eventually does the talk show circuit and writes her book, in which she meets a mysterious "fan," who says she deserves a better villain for her next case--then disappears.
- If everyone is alive, and Madison accompanies Ethan and Shaun out, they start a new life together. Norman seemingly gives up ARI, opting for the old fashioned method of police work, only to find he now hallucinates the virtual world in the *real* world. Shelby dies at Norman's hands (well, actually a giant machine shredder), and Norman does the talk show circuit. If Lauren is alive, she visits Shelby's grave and spits on it.
- You can also do the perfect crime, where Shelby covers his tracks the whole time (Hassan the store owner dies, you wipe all the fingerprints down in the antique store, et cetera), and all the other characters die. Shaun is never saved, and you see Shelby walking down the street, looking for his next father/son combo.