Secret Places (7)
Go to the bridge outside. If you look closely you'll find a thin ledge against the cliff wall. Climb it to find the hole that the gun turret is shooting from.
This handprint is outside just after the bridge. Press it to open a secret door below the bridge.
Look in the mess hall meat freezer for a bloody handprint. Press it to open a hidden door. Go into the hidden room and press on the computer to deactivate the forcefield.
Go to the barracks and look for the only bed with flashing lights. This bed works like an elevator. It will take you to a secret place.
Press on the hand-dryer in the washroom. Turn around quickly and you'll see a hidden door above the last toilet stall.
Use the blue access card to deactivate the forcefields and enter the room. Press on the computer shown in the image to open a hidden door on your right. Watch out for the pigcop behind the hidden door.
In the long hallway with all of the different doors, watch the wall on the left for a vent. Go through this vent and turn left after exiting it to find a powerswitch on the wall. This powerswitch opens the subway train in the room. The subway train is the secret place.
Secret Messages
"Are you small or are you cheating?". Found in the mess hall water current pathway (requires being shrunken or DNCLIP).
"Looking for secrets? - DUV". Found in the weather channel security camera room (requires DNCLIP, but using Build would be easier).
"C'mon, quit cheating - DUV". Found in the "your mission: destroy!" security camera room (requires DNCLIP, but using Build would be easier).