After Kat blows open the doors and asks for you to establish contact, press the Alert button.
As soon as Kat is attacked and asks for help, enter code 123 and press the Red button.
When you see some Blood Oranges dropping rocks down towards Kat, enter code 152 and press the Red button.
When Kat wakes up on the conveyor belt, wait for the side view, then press the E button to stop the conveyor. There will be a long fight between Kat and one of the Blood Oranges, then another will stand up on the conveyor; press E to start it up again.
After descending some stairs, Kat will be surrounded by Blood Oranges near the furnace. When Kat yells "This isn't a game", press the J button to open the chute. When Kat starts running towards the crane, press the G button and she will jump on to the hook.
Once Kat is hovering over the catwalk, press the G button again and she will drop down.
Now you need to guide Kat through the catwalk maze using the arrow keys (press these directions at the right time):
Kat will ask if you can see any water - press the "Yes" button, then guide her right and forward to reach the sink. Answer "Yes" to her next question as well. She will automatically go back out and through the double doors.
After Kat finds some drugs and the Blood Oranges start shooting at her, guide her to the right.
Kat will climb a ladder up the side of a water tower. Once she is slowly chased over a pipe at the top, enter code 666 and press the red button. Answer either way to Kat's question about turning on the showers. She will then walk through a cell block.
After freeing a prisoner and being knocked to the ground, wait until the Blood Orange says he has to kill you, then enter code 451 and press the Red button.
Kat will enter an elevator and use the controls. Once she looks up to see the elevator roof is not moving, enter code 911 and press the Red button.
While the General is taunting you, press the N button to sound the siren. This will cause a distraction long enough for Kat to dispose of him.