What are all the endings in one chance the game?

Answer 1

Ending S: Method: Chuck completes all cases, but saves TK with Zombrex (TK is Infected). This will unlock the Overtime Mode.

After defeating Raymond Sullivan and witholding the firebombing, Chuck lands on the rooftop of the safe house, but heads back into the safe house to collect Katey and Stacey. Inside the safe house, both Katey and Stacey are nowhere to be found. Chuck picks up Katey's dropped backpack, and stands there silently with it in his hands as the game seemingly ends.

This leads to Overtime Mode.

Ending A:

Method: Chuck completes all cases, but does not give TK Zombrex.

After withholding the firebombing, Chuck lands on the Safe House with the helicopter and finds Stacey and Katey, but Katey drops her backpack. Chuck goes to retrieve it, but just as he is about to pick it up, the zombified TK grabs his arm and forces him into the elevator full of Zombies. Chuck throws the backpack to Stacey, shouts for the chopper to lift off, and for Stacey to take care of Katey. As the chopper lifts off, the scene transitions briefly back to the elevator. Chuck is floored by the zombies, while the elevator doors close. Inside, Chuck is seen holding TK off before the screen fades.

A message states that a group of media choppers rescued the living survivors and that it remains unknown if Chuck died from being eaten, infected, if the resumption of the firebombing killed him, or if he somehow managed to escape. Chuck is cleared of the charges due to Stacey Forsythe's information. The outbreak comes to be known itself as "Fortune's End".